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