I cannot upload any music in my game!!!!!(I even used MP3 music!!)

Could someone help me?My game wont allow me to upload music even though I added MP3 music, a trigger connected them, and checked the codes.What did I do wrong?
https://flowlab.io/game/play/1393071

First, click the upload button, then choose the sound, press choose, and WAIT. DO NOT CLOSE OUT THE MUSIC BLOCK MENU UNTIL YOU HEAR THE SOUND PLAY.

if it still dose not work get some thing better than free adition.