Hi shimke,
Thanks for the suggestion!
It is possible to send audio into the jammr app using virtual audio cable software like VB-CABLE (Windows), JACK (Windows, Mac, and Linux), and BlackHole (Mac). Setting them up can be a little involved but they allow you to connect a DAW like Reaper, GarageBand, Ableton, etc as the microphone input to jammr. That way you can send audio into jammr.
Please only send audio into jammr that is compatible with the Creative Commons Attribution-ShareAlike 3.0 license:
https://jammr.net/terms.html.To make this easier it would be nice to have drum loops built into jammr. Hopefully this will be added to jammr in the future!