in the custom.blade.php file, css is linked:
<link rel="stylesheet" href="{{URL::asset('assets/bootstrap-4.1.3/bootstrap.min.css')}}">
it generates this location:
http://localhost.laravel/assets/bootstrap-4.1.3/bootstrap.min.css
but in this URL don't get the CSS file, I get error:

Server document_root for laravel app is:
/var/www/laravel/public
Here is the directory map:
here is the server configuration file: enter link description here
