How do i get cached audio to play?

Heya,

I'm new to twine, So apologies if i say a bunch of dumb stuff.
I'm trying to get one track to play with sugarcube 2.0 in the twine app.
I made a passage called StoryInit in which i placed

<<cacheaudio "song" "media/audio/song.mp3">>

Then in the start passage i put

<<audio "song" play>>

When i play in twine i get

Error: <<audio>>: no track by ID: song

What am I missing?

Thanks for any help.