How do you play a .mp3 file on Twine 2?

I'm currently using SugarCube 1.0.34, I have read a bunch of forum posts and stuff, but my code still doesn't work.
Right now the code I have cache the audio looks like this in my StoryInit passage:

<<cacheaudio "bgm_mainsoundtrack" "Users/Name/Documents/Twine/Dungeon_Soundtrack_Main.mp3">>

And my audio code looks like this:

<<audio "bgm_mainsoundtrack" play>>

However, the audio doesn't play. Can someone please tell me what I'm doing wrong?
Thanks so much!