I don’t get how to put my own music into the music box because when I convert the url into MP3, I don’t understand where to get the MP3 url itself, to put in the slot.

If your link ends in MP3, when you click to add a sound, there should be a rectangle that you click to type in, and just paste the link.

Capture 1
Capture 2
Capture 3

1st, open Sound-effect box.

2nd, Copy Mp3 URL (you can find out how by viewing my post and others in this discussion,

3rd, Paste URL into “Choose sound OR .mp3 URL” rectangle. You are done!