How license key management works in Parallels Plesk Panel

PP has a new automated Key Management System that allows the PP administrator to update the license directly from the PP interface under Tools&Settings (Server for earlier PP versions) -> License Management page. In order to eliminate fraud and theft of PP keys, an expiration date that requires a PP key to check in with a management system for renewal was implemented. In other words, a new PP key should be retrieved from the key management system every three months. This is done automatically by PP and does not require you to manage the license expiration unless an error occurs.

Please note that the license expiration date does not affect any key PP feature, such as SUS, email support, etc.
PP uses port 5224 to communicate with the key management system, so make sure that this port is opened in your firewall for outgoing connections. If PP fails to renew the key for some reason, you will see a note about it in the control panel. If you do not fix the issue with key updating and do not install a renewed key manually, the PP web interface will be blocked.