To install Flatpak on Kubuntu, open Discover, go to Settings, install the Flatpak backend and restart Discover.
To integrate Flatpak support into the Plasma System Settings, open the Terminal app and run:
Openpak is the best place to get Flatpak apps. To enable it, open Discover, go to Settings and add the Openpak repository.
To complete setup, restart your system. Now all you have to do is install apps!
