laravel 5.8 how to personlize messege in verification email?

I am new to Laravel, in Laravel 5.8 I am trying to personalize the message in verification email to be:

Hello $username;
Congrats now you are registered at our website
Please confirm this email is yours
.... 

what I want if you may kindly to tell me how to do this? also I want the default verification url of the button that is in verification email to stay as it is. in other words I want just to edit the text that is sent, how to do this?

via Chebli Mohamed