Place it as the last sound in an edit, after the final gameplay moment and before any outro card. Lead in with the Inception Horn for a dramatic final beat, then let this clip close the sequence and signal that the run is done.
Über diesen Sound
This short Undertale exit cue lasts about five and a half seconds, built around a simple melodic game sound rather than speech. It feels calm and final, like a door closing after a long journey, with a quiet sense of relief and goodbye. It suits the moment a player leaves the Underground and the story draws to a close.