Probably a satellite in low-earth orbit. They only take a few minutes to go from one horizon to the other. Since it is very bright, I am guessing it is the ISS.
Update: Iceland is too far north (64°N) to see the ISS (max 51.6°N). Too bad.
Was about to say, northern lights are not in the south as seen from Iceland so ISS would not be probable. It should be possible to figure out what high-inclination object was in the sky at the right time of day (it needs to reflect sunlight) on September 13th as the video description says it was shot on
Edit: or based on the fireball timing, mister detective here just realised. The comments even say "Is it possible that it was on 12.09.2023 at 22:35? We were in Höfn watching the northern lights when we saw it" and a reply confirms it
