WARNING: If you don't know what you're doing with php settings please do not touch these settings. A wrong entry can crash your website. We advise you to work with a developer to choose the settings that best suit your needs.
First login to your cPanel. (How to log into your cPanel)
To update your PHP Settings or Variables:
Search for 'php' and Click on 'Select PHP Version'
Next click on 'Options'
Edit your settings and your changes will be automatically saved.