Since version 54, cPanel has a tool called MultiPHP Manager, which comes with EasyApache4. New servers will have it installed by default, while older servers can update from EasyApache3 by running a conversion script.
MultiPHP Manager allows cPanel accounts to change the version of PHP their website use, on a per-website basis.
To change the PHP version, first log into the cPanel and find the MultiPHP Manager icon:
Select which website you want to change the version on, select the version and click apply:
If you find that website has a problem with the different version, you can always change it back. The change is instantaneous.