Here is a very simple way to find the file name that contains the environment variables PHP_FCGI_MAX_REQUESTS and PHP_FCGI_CHILDREN:
1. Create a PHP file e.g. "abc.php" and put the following code in it to get the PHP information.
<?php phpinfo(); ?>
2. Put the above PHP file in the home directory of your website.
3. Access the file from a browser and search for the keyword "Environment". If your server API is "CGI/FCGI", you will find variables PHP_FCGI_MAX_REQUESTS and PHP_FCGI_CHILDREN under "Environment". The value of the variable "PWD" will show you the folder name that contains the file you need to modify to change the value of those variables. If you go to that folder, the filename should be similar to "fcgi-xxx".