Where Is the Repeat Button on Spotify?
It looks like two white arrows in a loop.
This location is consistent for all platform versions of the Spotify player.

The image below is from the Spotify desktop player.
How Do I Loop a Song on the Spotify Mobile App?
The location and behavior of the Repeat button on Spotify are the same across all platforms.

Here’s how to enable repeat.
We happen to be using an iPhone here, but it’s the same on Android.
fire up the Spotify app on iPhone.
Play the song you want to listen to on repeat.
It can be an individual track or part of a playlist.
Tap once on theNow Playingbar to maximize the album art and the playback controls.
Tap theRepeatbutton once to turn it green.
It will switch on the playlist to play on repeat.
Tap the Repeat button twice in succession to turn it green and display a small1.
It will loop the song on repeat till you turn it off.
Tap it again to stop the song playing on repeat.
Why Cant I Put a Song on Repeat on Spotify?
The Repeat feature is available on the Android and iOS apps for Spotify Premium account users.
Remember, in the mobile app, you have to tap theNow Playingbar to access theRepeatbutton.
How Do You Repeat a Song on Spotify Without Premium?
FAQ
Launch the Spotify web player and locate the song you want to put on repeat.
Play the song, and then find theRepeatbutton in the media controls.
Press theRepeatbutton twice; it will turn green and display a1.
Press theRepeatbutton again to stop repeating the song.
Unfortunately, it’s possible for you to’t put a podcast on repeat with Spotify.
To repeat an album or playlist on Spotify, begin playing it, and press theRepeatbutton once.
The Repeat button will turn green, but it won’t display a1as if you pressed the button twice.
The playlist or album will play through and then begin playing again.
If you press theRepeatbutton twice and it displays a1, the current song will play on a loop.