Unfortunately, that's worse. I don't want to repeat the song, I want the app to stop after one song. I have found no way to play only one song. It will continue playing and clicking on the infinity symbol does nothing. I've called Apple 3 times and chatted online once and nobody has a solution.
I believe there isn't one. I've had to resort to downloading third party apps to play music on my iPad and iPhone. And of course other apps can't find my Apple Music library. I have been using an ancient iPad to listen to things before sleep, often lectures that are mp3s, and am able to stop after one. With the new iPad I wake up in the morning with music still on after playing all night long.
Not good for the quality of my sleep and other good for the battery. Really annoying. For me upgrading to a new iPad was a waste of money since it can't do what the old one did.