1. Log into your cPanel account.
2. In the "Software" section, click on the "MultiPHP Manager" Icon.
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3. Scroll down to the bottom of the page, select your domain from the left side of the screen and you will see an option "PHP Version" with a drop-down menu on the right side. Select the appropriate PHP version from it and click the Apply button.
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If will take a few seconds and then your PHP version will change to your selected version.