How to Edit Your php.ini File on cPanel

On systems that run EasyApache 3, the /usr/local/lib/ directory contains your server’s php.ini file.
On systems that run EasyApache 4, multiple php.ini and local.ini files manage your system’s PHP. Each version of PHP on your systems uses its own php.ini and local.ini file. You must make changes to each file separately.

On systems that run EasyApache 3, we strongly recommend that you only edit this file with WHM’s PHP Configuration Editor interface (Home >> Service Configuration >> PHP Configuration Editor).

On systems that run EasyApache 4, we strongly recommend that you only edit these files with WHM’s MultiPHP INI Editor interface (Home >> Software >> MultiPHP INI Editor). This ensures that an operable version of PHP exists on the system.

Resource: https://documentation.cpanel.net/display/CKB/How+to+Edit+Your+php.ini+File