Follow the Steps:-
1. Login to cPanel > Home
2. Select the Software option
4.  Go to MultiPHP Manager option
5. Select the domain for which you wish to change PHP version
6. Select PHP version  > Apply
Follow the Steps:-
1. Login to cPanel > Home
2. Select the Software option
4.  Go to MultiPHP Manager option
5. Select the domain for which you wish to change PHP version
6. Select PHP version  > Apply