Hi NaviX,
For most protocols you can use ?audio=<trackid>&video=<trackid>.
If it's easier you can view the stream you want the url from on the preview tab of the Management Interface. Open the browser's development console (F12), go to the network tab. If you choose the protocol and track you want in the player, you'll see a network request appear. Just copy the url from there.
I hope that helps, feel free to ask if you run into anything.
Kind regards,
Carina van der Meer