If you want to set individual settings for PHP on a server with Directadmin and Custombuild 2, then for php-fpm and php-fastcgi you can use the following instructions.
For fastcgi create a file:
Replace USERNAME, DOMAIN with your real username and domain.
Add your instructions for PHP into the file and restart apache.
For PHP-FPM it is:
Add your instructions for PHP into the file (or modify existing) and restart apache php-fpm.
Replace USERNAME and PHPVER with your real data.