Question
Where are the PHP-FPM configuration files located?
Answer
The PHP-FPM configuration files that would be used globally either domain pools or systems settings would be located in:
/var/cpanel/ApachePHPFPM
The domain PHP-FPM settings are located in the domains userdata folder for example located at:
/var/cpanel/userdata/cpuser/somedomain.com.php-fpm.yaml
More details on these locations, files and directives that can be set is located at: Configuration Values of PHP-FPM