How to play mp3 file in endless loop on iPhone?

Hello Stonytech,

This article shows you how to repeat a song on your iPhone: How to repeat music on your iPhone

How to repeat a song

1. Open the Apple Music app.

2. Play a song.

3. Tap the song that's playing at the bottom of the screen.

4. In the screen that appears, tap the Playing Next button  in the lower-right corner.

5. At the top of the Playing Next screen, tap the Repeat button until it changes to Repeat One. When the Repeat button is highlighted with a number 1, Repeat One is turned on.

Best Regards.