Ubuntu 22.04 LTS (Jammy Jellyfish) was released a couple of weeks ago. However, it seems that pmm2-client is not yet available in your repos:
$ sudo percona-release enable pmm2-client
Specified repository is not supported for current operating system!
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04 LTS
$ dpkg -s percona-release | grep ^Version
Do you plan to release a version for Ubuntu 22.04 soon?