Right here
https://benonistudio.com/tutorials/s...ing-tutorials/
There are many ways to route the audio. Easiest way is two interfaces or one interface with Loopback.
Other options are Voicemeeter or for really simple stuff, the FL Studio driver.
OBS is free, and I go over your options in may of the videos, mainly for recording, but you can stream with it too.
Streamlabs OBS is another free option that makes it a bit easier specifically for streaming.
I'll have another video out later today about using Loopback with the Evo 8 and OBS
www.youtube.com/benonistudio
Even if you don't have the Evo 8, the process inside OBS is exactly the same for any Loopback capable interface.