This script shows you the PHP configuration on the server

<?php

phpinfo();

?>

This is a baked in function of PHP, so it doesn’t look like much until you run it.
Save the code in a file called phpinfo.php and upload to the webserver.

Visiting domain.com/phpinfo.php will show something like this:

An example of this is located here: https://tech.chrisapp.co.uk/PHP/phpinfo.php