How do I read a list of mp3 files on the phone and select a song for certain buttons?

I'm doing a app for a educational device, and the teacher need to do some mp3 lessons every week.
The app have 12 pages of contents with these lessons in audio, and the lesson start when these page is open, and have 3 buttons to play, pause and stop.
I need to create a configuration screen where I can put a list of all mp3 in a specific folder in internal storage, and select the specific file to assign to buttons of each lesson.
It is possible?

You should use a File Manager extension.

File Extension is an extension related to the File component, by Taifun

FileTools Extension by vknow360