Expected response code 250 but got code "530", with message "530-5.7.0 Authentication Required

I've deployed my web app on Heroku but there are some things which are giving me an error when I'm trying to register a new user in the web app. The registration works fine on my localhost and it even sends the new users an email whenever they register an account. But on heroku, it displays the following error whenever I try to register an new user. 'Expected response code 250 but got code "530", with message "530-5.7.0 Authentication Required'.

I've also noted that the .env file doesn't show on my github whenever I push so I had to put the env file on heroku config settings.

Here's my code on my .env file and mail.php.

MAIL_MAILER=smtp
MAIL_HOST=smtp.googlemail.com
MAIL_PORT=465
MAIL_USERNAME=ben@gmail.com
MAIL_PASSWORD=****************
MAIL_ENCRYPTION=ssl
MAIL_FROM_ADDRESS=ben@gmail.

'default' => env('MAIL_MAILER', 'smtp'),
'from' => [
    'address' => env('MAIL_FROM_ADDRESS', 'hello@example.com'),
    'name' => env('MAIL_FROM_NAME', 'Example'),
],

And here are my setting on heroku displayed on this .

If you can, please show me a way of how to get around this error.

via Chebli Mohamed