How can I improve the TTFB for Laravel project?

I engaged with a Laravel AMP project which uses Laravel 5.6. The project is launched in the server (apache http server) and running (also running other 4 sites on the same server). The server has:

• Processor : Intel(R) Xeon(R) CPU E3-1220 v3 @ 3.10GHz
• Memory : 16226420 kB (16GB)

When I checked the page with Webpagetest, it shows F grade for First Byte Time.

How can I improve the performance of First Time Byte to grade "A"?

Information about First Byte Time

WaterFall

And I have the following content in the .htaccess file which in the public_html folder.

# Apache configuration file
# httpd.apache.org/docs/2.2/mod/quickreference.html

# Note .htaccess files are an overhead, this logic should be in your Apache
# config if possible: httpd.apache.org/docs/2.2/howto/htaccess.html

# Techniques in here adapted from all over, including:
#   Kroc Camen: camendesign.com/.htaccess
#   perishablepress.com/press/2006/01/10/stupid-htaccess-tricks/
#   Sample .htaccess file of CMS MODx: modxcms.com


# ----------------------------------------------------------------------
# Better website experience for IE users
# ----------------------------------------------------------------------

# Force the latest IE version, in various cases when it may fall back to IE7 mode
#  github.com/rails/rails/commit/123eb25#commitcomment-118920

RewriteEngine on

RewriteCond %{HTTP_HOST} ^www\.(.*)$ [NC]
RewriteRule ^(.*)$ https://%1/$1 [R=301,L]
RewriteCond %{ENV:HTTPS} !on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]


#RewriteCond %{HTTPS}s ^on(s)|
#RewriteRule ^(.*)$ http%1://www.%{HTTP_HOST}/$1 [R=301,L]




<IfModule mod_headers.c>
  Header set X-UA-Compatible "IE=Edge"
  # mod_headers can't match by content-type, but we don't want to send this header on *everything*...
  <FilesMatch "\.(appcache|crx|css|eot|gif|htc|ico|jpe?g|js|m4a|m4v|manifest|mp4|oex|oga|ogg|ogv|otf|pdf|png|safariextz|svg|svgz|ttf|vcf|webm|webp|woff|woff2|xml|xpi)$">
    Header unset X-UA-Compatible
  </FilesMatch>
</IfModule>


# ----------------------------------------------------------------------
# Cross-domain AJAX requests
# ----------------------------------------------------------------------

# Serve cross-domain Ajax requests, disabled by default.
# enable-cors.org
# code.google.com/p/html5security/wiki/CrossOriginRequestSecurity

#  <IfModule mod_headers.c>
#    Header set Access-Control-Allow-Origin "*"
#  </IfModule>


# ----------------------------------------------------------------------
# CORS-enabled images (@crossorigin)
# ----------------------------------------------------------------------

# Send CORS headers if browsers request them; enabled by default for images.
# developer.mozilla.org/en/CORS_Enabled_Image
# blog.chromium.org/2011/07/using-cross-domain-images-in-webgl-and.html
# hacks.mozilla.org/2011/11/using-cors-to-load-webgl-textures-from-cross-domain-images/
# wiki.mozilla.org/Security/Reviews/crossoriginAttribute

<IfModule mod_setenvif.c>
  <IfModule mod_headers.c>
    # mod_headers, y u no match by Content-Type?!
    <FilesMatch "\.(gif|ico|jpe?g|png|svg|svgz|webp)$">
      SetEnvIf Origin ":" IS_CORS
      Header set Access-Control-Allow-Origin "*" env=IS_CORS
    </FilesMatch>
  </IfModule>
</IfModule>


# ----------------------------------------------------------------------
# Webfont access
# ----------------------------------------------------------------------

# Allow access from all domains for webfonts.
# Alternatively you could only whitelist your
# subdomains like "subdomain.example.com".

<IfModule mod_headers.c>
  <FilesMatch "\.(eot|font.css|otf|ttc|ttf|woff|woff2)$">
    Header set Access-Control-Allow-Origin "*"
  </FilesMatch>
</IfModule>


# ----------------------------------------------------------------------
# Proper MIME type for all files
# ----------------------------------------------------------------------

# JavaScript
#   Normalize to standard type (it's sniffed in IE anyways)
#   tools.ietf.org/html/rfc4329#section-7.2
AddType application/javascript         js jsonp
AddType application/json               json

# Audio
AddType audio/mp4                      m4a f4a f4b
AddType audio/ogg                      oga ogg

# Video
AddType video/mp4                      mp4 m4v f4v f4p
AddType video/ogg                      ogv
AddType video/webm                     webm
AddType video/x-flv                    flv

# SVG
#   Required for svg webfonts on iPad
#   twitter.com/FontSquirrel/status/14855840545
AddType     image/svg+xml              svg svgz
AddEncoding gzip                       svgz

# Webfonts
AddType application/vnd.ms-fontobject  eot
AddType application/x-font-ttf         ttf ttc
AddType application/x-font-woff        woff
AddType application/x-font-woff        woff2
AddType font/opentype                  otf

# Assorted types
AddType application/octet-stream            safariextz
AddType application/x-chrome-extension      crx
AddType application/x-opera-extension       oex
AddType application/x-shockwave-flash       swf
AddType application/x-web-app-manifest+json webapp
AddType application/x-xpinstall             xpi
AddType application/xml                     rss atom xml rdf
AddType image/webp                          webp
AddType image/x-icon                        ico
AddType text/cache-manifest                 appcache manifest
AddType text/vtt                            vtt
AddType text/x-component                    htc
AddType text/x-vcard                        vcf


# ----------------------------------------------------------------------
# Allow concatenation from within specific js and css files
# ----------------------------------------------------------------------

# e.g. Inside of script.combined.js you could have
#   <!--#include file="libs/jquery-1.5.0.min.js" -->
#   <!--#include file="plugins/jquery.idletimer.js" -->
# and they would be included into this single file.

# This is not in use in the boilerplate as it stands. You may
# choose to use this technique if you do not have a build process.

#<FilesMatch "\.combined\.js$">
#  Options +Includes
#  AddOutputFilterByType INCLUDES application/javascript application/json
#  SetOutputFilter INCLUDES
#</FilesMatch>

#<FilesMatch "\.combined\.css$">
#  Options +Includes
#  AddOutputFilterByType INCLUDES text/css
#  SetOutputFilter INCLUDES
#</FilesMatch>


# ----------------------------------------------------------------------
# Gzip compression
# ----------------------------------------------------------------------

<IfModule mod_deflate.c>

  # Force deflate for mangled headers developer.yahoo.com/blogs/ydn/posts/2010/12/pushing-beyond-gzipping/
  <IfModule mod_setenvif.c>
    <IfModule mod_headers.c>
      SetEnvIfNoCase ^(Accept-EncodXng|X-cept-Encoding|X{15}|~{15}|-{15})$ ^((gzip|deflate)\s*,?\s*)+|[X~-]{4,13}$ HAVE_Accept-Encoding
      RequestHeader append Accept-Encoding "gzip,deflate" env=HAVE_Accept-Encoding
    </IfModule>
  </IfModule>

  # Compress all output labeled with one of the following MIME-types
  # (for Apache versions below 2.3.7, you don't need to enable `mod_filter`
  # and can remove the `<IfModule mod_filter.c>` and `</IfModule>` lines as
  # `AddOutputFilterByType` is still in the core directives)
  <IfModule mod_filter.c>
    AddOutputFilterByType DEFLATE application/atom+xml \
                                  application/javascript \
                                  application/json \
                                  application/rss+xml \
                                  application/vnd.ms-fontobject \
                                  application/x-font-ttf \
                                  application/x-font-truetype
                                  application/xhtml+xml \
                                  application/xml \
                                  font/opentype \
                                  image/svg+xml \
                                  image/x-icon \
                                  text/css \
                                  text/html \
                                  text/plain \
                                  text/x-component \
                                  text/xml
  </IfModule>

</IfModule>

<ifModule mod_gzip.c>
mod_gzip_on Yes
mod_gzip_dechunk Yes
mod_gzip_item_include file .(html?|txt|css|js|php|pl)$
mod_gzip_item_include handler ^cgi-script$
mod_gzip_item_include mime ^text/.*
mod_gzip_item_include mime ^application/x-javascript.*
mod_gzip_item_exclude mime ^image/.*
mod_gzip_item_exclude rspheader ^Content-Encoding:.*gzip.*
</ifModule>

# ----------------------------------------------------------------------
# Expires headers (for better cache control)
# ----------------------------------------------------------------------

# These are pretty far-future expires headers.
# They assume you control versioning with filename-based cache busting
# Additionally, consider that outdated proxies may miscache
#   www.stevesouders.com/blog/2008/08/23/revving-filenames-dont-use-querystring/

# If you don't use filenames to version, lower the CSS and JS to something like
# "access plus 1 week".

<IfModule mod_expires.c>
  ExpiresActive on

# Perhaps better to whitelist expires rules? Perhaps.
  ExpiresDefault                          "access plus 1 year"

# cache.appcache needs re-requests in FF 3.6 (thanks Remy ~Introducing HTML5)
  ExpiresByType text/cache-manifest       "access plus 0 seconds"

# Your document html
  ExpiresByType text/html                 "access plus 0 seconds"

# Data
  ExpiresByType application/json          "access plus 0 seconds"
  ExpiresByType application/xml           "access plus 0 seconds"
  ExpiresByType text/xml                  "access plus 0 seconds"

# Feed
  ExpiresByType application/atom+xml      "access plus 1 hour"
  ExpiresByType application/rss+xml       "access plus 1 hour"

# Favicon (cannot be renamed)
  ExpiresByType image/x-icon              "access plus 1 week"

# Media: images, video, audio
  ExpiresByType audio/ogg                 "access plus 1 year"
  ExpiresByType image/gif                 "access plus 1 year"
  ExpiresByType image/jpeg                "access plus 1 year"
  ExpiresByType image/webp                "access plus 1 year"
  ExpiresByType image/png                 "access plus 1 year"
  ExpiresByType video/mp4                 "access plus 1 year"
  ExpiresByType video/ogg                 "access plus 1 year"
  ExpiresByType video/webm                "access plus 1 year"


# HTC files  (css3pie)
  ExpiresByType text/x-component          "access plus 1 month"

# Webfonts
  ExpiresByType application/vnd.ms-fontobject "access plus 1 month"
  ExpiresByType application/x-font-ttf    "access plus 1 year"
  ExpiresByType application/x-font-woff   "access plus 1 year"
  ExpiresByType font/opentype             "access plus 1 year"
  ExpiresByType image/svg+xml             "access plus 1 year"

# CSS and JavaScript
  ExpiresByType application/javascript    "access plus 1 year"
  ExpiresByType text/css                  "access plus 1 year"

</IfModule>


# ----------------------------------------------------------------------
# Prevent mobile network providers from modifying your site
# ----------------------------------------------------------------------

# The following header prevents modification of your code over 3G on some
# European providers.
# This is the official 'bypass' suggested by O2 in the UK.

# <IfModule mod_headers.c>
# Header set Cache-Control "no-transform"
# </IfModule>


# ----------------------------------------------------------------------
# ETag removal
# ----------------------------------------------------------------------

# FileETag None is not enough for every server.
<IfModule mod_headers.c>
  Header unset ETag
</IfModule>

# Since we're sending far-future expires, we don't need ETags for
# static content.
#   developer.yahoo.com/performance/rules.html#etags
FileETag None


# ----------------------------------------------------------------------
# Stop screen flicker in IE on CSS rollovers
# ----------------------------------------------------------------------

# The following directives stop screen flicker in IE on CSS rollovers - in
# combination with the "ExpiresByType" rules for images (see above).

# BrowserMatch "MSIE" brokenvary=1
# BrowserMatch "Mozilla/4.[0-9]{2}" brokenvary=1
# BrowserMatch "Opera" !brokenvary
# SetEnvIf brokenvary 1 force-no-vary


# ----------------------------------------------------------------------
# Set Keep-Alive Header
# ----------------------------------------------------------------------

# Keep-Alive allows the server to send multiple requests through one
# TCP-connection. Be aware of possible disadvantages of this setting. Turn on
# if you serve a lot of static content.

# <IfModule mod_headers.c>
#   Header set Connection Keep-Alive
# </IfModule>


# ----------------------------------------------------------------------
# Cookie setting from iframes
# ----------------------------------------------------------------------

# Allow cookies to be set from iframes (for IE only)
# If needed, specify a path or regex in the Location directive.

# <IfModule mod_headers.c>
#   Header set P3P "policyref=\"/w3c/p3p.xml\", CP=\"IDC DSP COR ADM DEVi TAIi PSA PSD IVAi IVDi CONi HIS OUR IND CNT\""
# </IfModule>


# ----------------------------------------------------------------------
# Start rewrite engine
# ----------------------------------------------------------------------

# Turning on the rewrite engine is necessary for the following rules and
# features. FollowSymLinks must be enabled for this to work.

# Some cloud hosting services require RewriteBase to be set: goo.gl/HOcPN
# If using the h5bp in a subdirectory, use `RewriteBase /foo` instead where
# 'foo' is your directory.

# If your web host doesn't allow the FollowSymlinks option, you may need to
# comment it out and use `Options +SymLinksIfOwnerMatch`, but be aware of the
# performance impact: http://httpd.apache.org/docs/2.2/misc/perf-tuning.html#symlinks

<IfModule mod_rewrite.c>
  <IfModule mod_negotiation.c>
    Options -MultiViews -Indexes
  </IfModule>

  RewriteEngine On

  # Handle Authorization Header
  RewriteCond %{HTTP:Authorization} .
  RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

  # Redirect Trailing Slashes If Not A Folder...
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_URI} (.+)/$
  RewriteRule ^ %1 [L,R=301]

  # Handle Front Controller...
  RewriteCond %{REQUEST_FILENAME} !-d
  RewriteCond %{REQUEST_FILENAME} !-f
  RewriteRule ^ index.php [L]
</IfModule>


<IfModule LiteSpeed>
CacheEnable public
RewriteEngine On
RewriteCond %{REQUEST_METHOD} ^GET|HEAD$
RewriteCond %{HTTP_HOST} ^mytestweb.com [NC]
RewriteCond %{REQUEST_URI} !login|admin|register|post|cron    
RewriteCond %{QUERY_STRING} !nocache
RewriteRule .* - [E=Cache-Control:max-age=300]
</IfModule>


# ----------------------------------------------------------------------
# Suppress or force the "www." at the beginning of URLs
# ----------------------------------------------------------------------

# The same content should never be available under two different URLs -
# especially not with and without "www." at the beginning, since this can cause
# SEO problems (duplicate content). That's why you should choose one of the
# alternatives and redirect the other one.

# By default option 1 (no "www.") is activated.
# no-www.org/faq.php?q=class_b

# If you'd prefer to use option 2, just comment out all option 1 lines
# and uncomment option 2.

# IMPORTANT: NEVER USE BOTH RULES AT THE SAME TIME!

# ----------------------------------------------------------------------

# Option 1:
# Rewrite "www.example.com -> example.com".
#aaa
#<IfModule mod_rewrite.c>
#  RewriteCond %{HTTPS} !=on
#  RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
#  RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L]
#</IfModule>

# ----------------------------------------------------------------------

# Option 2:
# Rewrite "example.com -> www.example.com".
# Be aware that the following rule might not be a good idea if you use "real"
# subdomains for certain parts of your website.

 #<IfModule mod_rewrite.c>
 #  RewriteCond %{HTTPS} !=on
 #  RewriteCond %{HTTP_HOST} !^www\..+$ [NC]
 #  RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
 #</IfModule>


# ----------------------------------------------------------------------
# Built-in filename-based cache busting
# ----------------------------------------------------------------------

# If you're not using the build script to manage your filename version revving,
# you might want to consider enabling this, which will route requests for
# `/css/style.20110203.css` to `/css/style.css`.

# To understand why this is important and a better idea than all.css?v1231,
# please refer to the bundled documentation about `.htaccess`.

# <IfModule mod_rewrite.c>
#   RewriteCond %{REQUEST_FILENAME} !-f
#   RewriteCond %{REQUEST_FILENAME} !-d
#   RewriteRule ^(.+)\.(\d+)\.(js|css|png|jpg|gif)$ $1.$3 [L]
# </IfModule>


# ----------------------------------------------------------------------
# Prevent SSL cert warnings
# ----------------------------------------------------------------------

# Rewrite secure requests properly to prevent SSL cert warnings, e.g. prevent
# https://www.example.com when your cert only allows https://secure.example.com

<IfModule mod_rewrite.c>
  RewriteCond %{SERVER_PORT} !^443   
  RewriteRule ^ https://mytestweb.com%{REQUEST_URI} [R=301,L]
</IfModule>



# ----------------------------------------------------------------------
# Prevent 404 errors for non-existing redirected folders
# ----------------------------------------------------------------------

# without -MultiViews, Apache will give a 404 for a rewrite if a folder of the
# same name does not exist.
# webmasterworld.com/apache/3808792.htm

Options -MultiViews


# ----------------------------------------------------------------------
# Custom 404 page
# ----------------------------------------------------------------------

# You can add custom pages to handle 500 or 403 pretty easily, if you like.
# If you are hosting your site in subdirectory, adjust this accordingly
#    e.g. ErrorDocument 404 /subdir/404.html
ErrorDocument 404 /404.html


# ----------------------------------------------------------------------
# UTF-8 encoding
# ----------------------------------------------------------------------

# Use UTF-8 encoding for anything served text/plain or text/html
AddDefaultCharset utf-8

# Force UTF-8 for a number of file formats
AddCharset utf-8 .atom .css .js .json .rss .vtt .xml


# ----------------------------------------------------------------------
# A little more security
# ----------------------------------------------------------------------

# To avoid displaying the exact version number of Apache being used, add the
# following to httpd.conf (it will not work in .htaccess):
# ServerTokens Prod

# "-Indexes" will have Apache block users from browsing folders without a
# default document Usually you should leave this activated, because you
# shouldn't allow everybody to surf through every folder on your server (which
# includes rather private places like CMS system folders).
<IfModule mod_autoindex.c>
  Options -Indexes
</IfModule>

# Block access to "hidden" directories or files whose names begin with a
# period. This includes directories used by version control systems such as
# Subversion or Git.
<IfModule mod_rewrite.c>
  RewriteCond %{SCRIPT_FILENAME} -d [OR]
  RewriteCond %{SCRIPT_FILENAME} -f
  RewriteRule "(^|/)\." - [F]
</IfModule>

# Block access to backup and source files. These files may be left by some
# text/html editors and pose a great security danger, when anyone can access
# them.
<FilesMatch "(\.(bak|config|dist|fla|inc|ini|log|psd|sh|sql|swp)|~)$">
  Order allow,deny
  Deny from all
  Satisfy All
</FilesMatch>

# If your server is not already configured as such, the following directive
# should be uncommented in order to set PHP's register_globals option to OFF.
# This closes a major security hole that is abused by most XSS (cross-site
# scripting) attacks. For more information: http://php.net/register_globals
#
# IF REGISTER_GLOBALS DIRECTIVE CAUSES 500 INTERNAL SERVER ERRORS:
#
# Your server does not allow PHP directives to be set via .htaccess. In that
# case you must make this change in your php.ini file instead. If you are
# using a commercial web host, contact the administrators for assistance in
# doing this. Not all servers allow local php.ini files, and they should
# include all PHP configurations (not just this one), or you will effectively
# reset everything to PHP defaults. Consult www.php.net for more detailed
# information about setting PHP directives.

# php_flag register_globals Off

# Rename session cookie to something else, than PHPSESSID
# php_value session.name sid

# Disable magic quotes (This feature has been DEPRECATED as of PHP 5.3.0 and REMOVED as of PHP 5.4.0.)
# php_flag magic_quotes_gpc Off

# Do not show you are using PHP
# Note: Move this line to php.ini since it won't work in .htaccess
# php_flag expose_php Off

# Level of log detail - log all errors
# php_value error_reporting -1

# Write errors to log file
# php_flag log_errors On

# Do not display errors in browser (production - Off, development - On)
# php_flag display_errors Off

# Do not display startup errors (production - Off, development - On)
# php_flag display_startup_errors Off

# Format errors in plain text
# Note: Leave this setting 'On' for xdebug's var_dump() output
# php_flag html_errors Off

# Show multiple occurrence of error
# php_flag ignore_repeated_errors Off

# Show same errors from different sources
# php_flag ignore_repeated_source Off

# Size limit for error messages
# php_value log_errors_max_len 1024

# Don't precede error with string (doesn't accept empty string, use whitespace if you need)
# php_value error_prepend_string " "

# Don't prepend to error (doesn't accept empty string, use whitespace if you need)
# php_value error_append_string " "

# Increase cookie security
<IfModule mod_php5.c>
  php_value session.cookie_httponly true
</IfModule>

via Chebli Mohamed