How to: Gstreamer VA-API OBS Debian Flatpak, under 6min
Update: On debian 12.4.0 and KDE and Wayland, install
runtime/org.freedesktop.Platform.GStreamer.gstreamer-vaapi/x86_64/22.08
NOT
runtime/org.freedesktop.Platform.GStreamer.gstreamer-vaapi/x86_64/23.08
AND
sudo apt install pipewire, reboot and it worked
