The cPanel software does not support in-place operating system upgrades, to upgrade your OS to a new release or a supported operating system, we recommend acquiring a new server with a fresh supported operating system installation upon which cPanel & WHM may be installed. We can even install cPanel & WHM on your new server at your request.
Currently supported operating systems are CentOS 7, CentOS 8, CloudLinux 7, CloudLinux 8, Ubuntu 20.04, or AlmaLinux but please see our documentation on this matter.
Once you have a server with a supported operating system and cPanel & WHM, you may perform a cPanel to cPanel transfer using the Transfer Tool! The cPanel-to-cPanel transfer process using the Transfer Tool is seamless, and you can find more details on the Transfer Tool here: Transfer Tool.