Can't import my music

I'm trying to develop for Meta Horizon Worlds with the Desktop editor, but I can't upload my own music which is vital to my project as it is a rhythm based game.  Why is that because the documentation state that I should be able to add my own audio files.  What is wrong here?  And when will this be fixed.  I would like to submit my game for the Horizon Worlds Hackathon, but I can not if I can't upload my own custom music.  I wrote this music so there are no legal issues here. 

See here... the current Horizon worlds Desktop editor doesn't have this audio input interface:
https://developers.meta.com/horizon-worlds/learn/documentation/desktop-editor/assets/creating-importing-viewing-and-spawning-assets