There are many benefits to using the latest PHP version. The most important of all are: speed and safety.
Each new php version uses significantly less code, and the one that exists is optimized and thus the site without any changes, and using the newer PHP version is much faster. This can be noticed the most if you use, say, an outdated one like 5.6 and install 7.4.
Security, older versions are just old. Version 5.6 is over 10 years old. The Internet changes on a daily basis, new versions of all software are released weekly or monthly, and the site itself must keep up with the times if you want it to be fast and secure.
PHP version is changed from cPanel.
Instructions for accessing cPanel. After entering cPanel, look for the MultiPHP Manager icon and you can also start typing at the top and it will show you.
After you find it, a list of all the domains you have on that hosting account will open. If you have one it will list that one.
What you need is to tick the domain (even if it is only one domain) and then select the PHP version from the right corner and then click on the apply button.
The site is not working after the change.
If the site does not work after the change, then something on your site or the site itself does not support that version. If you want to go to the council (and that is certainly a recommendation), then you need to see what the problem is. If you have wordpress, then it is probably a plugin or, in the worst case, a theme (because it requires a redesign of the site). How to see what it requires, simply turn on debug on your site and then see what it will report and if it's a plugin, then replace it with a modern one, because apparently that one is no longer functional and is not being upgraded.
You can see how to find the problem and how to solve it at this link:
Internal server error 500 how analysis occurs
