Tried on my Steam Deck and my EndeavourOS PC.
Tried both flatpak and build from source on the Deck, could barely get anything to work past the test button. It did briefly allow me to add assets, but for the most part has not worked.
On EndeavourOS, I have Firefox and SGDboop installed through terminal and for some reason only "Boope them all" works. No individual assets.
If you need extra info let me know.