Install the Punktfunk Linux client (auto-adds Flathub for the GNOME runtime, then tracks updates).
Stable (recommended — only moves on releases):
flatpak install --user https://flatpak.unom.io/io.unom.punktfunk.flatpakref flatpak run io.unom.punktfunk
Canary (latest main build, unstable):
flatpak install --user https://flatpak.unom.io/io.unom.punktfunk.canary.flatpakref
Or add the whole remote: flatpak remote-add --user --if-not-exists unom https://flatpak.unom.io/unom.flatpakrepo