Updating the ISPConfig server from Ubuntu 20.04 to Ubuntu 22.04 is explained in a tutorial published by Howtoforge.

Update the ISPConfig Perfect Server from Ubuntu 20.04 to Ubuntu 22.04

This tutorial will take you through updating a server managed by ISPConfig from Ubuntu 20.04 (Focal Fossa) to Ubuntu 22.04 (Jammy Jellyfish).

Update the ISPConfig Perfect Server from Ubuntu 20.04 to Ubuntu 22.04