If the managed website is moved to the new webservers already, it's possible to request the change of the PHP version on the webhosting portal. After going to My URLs > Details, there is a point PHP version under overview, where the desired version can be choosed and confirmed with the button "Request Change".

Please note that PHP version changes can be configured from version 7.4. We recommend version 8.0 or 8.1. If your Webspace does not support this version, please revert to version 7.4.