Exporting files from Prime
You have to buy the zip file version of the song. There are two versions of tracks 1. In App Only and 2. In App and Zip. The In App Only lets you use the track in the app only and the second one gives you the potential to use it in prime but you also get a zip file of all the inidivdual wav channels. Number 2 is more expensive by a little but lets you use it anywhere. If you already bought the In App only you can upgrade to the zip for $15. You lost some money if you do the math of the two but it's cheaper then rebuying the track
Unfortunately, you can't export audio directly from the Prime app. However, you can purchase the file download version of any track from Loop so that you can use the audio in other programs!