How do I export a recording showing the different tracks

My partner has just made a recording that is in 3 parts. How can I export it as one recording with 3 tracks like an EP/Album in mp3
Thanks in advance

You can’t have multiple tracks in one MP3. You’ll have to make 3 separate tracks. See [u]Splitting A Recording Into Separate Tracks[/u].

If you’re making a CD, you can have a continuous program with track markers. There is a way to add chapters to an AAC file for an audio book, but I don’t know how to do it, and your player software has to support that feature.

One can create EP-type arrangements of tracks on SoundCloud, for free, e.g. …
https://soundcloud.com/makoandthehawk/sets/mako-mr-bristow-supersoul [ track #2 is best]