Hi all,
Had that same requirement for online instrument classes.
My solution was to use Voicemeeter Banana.
I have the Helix and the webcam microphone as separate hardware inputs in Voicemeeter, the computer sounds go to Voicemeeter VAIO (to mix in a backing track from Youtube or other source).
Then on Zoom, I set the microphone as the Voicemeeter VAIO (everything you mix in the VAIO channel will be sent to Zoom) and the speaker as the Voicemeeter Aux.
After that, I set one of the output channels to my PC headphone out.
Now I can decide what I want to hear trough the headphones (my bass, the backing track, the sound from my teacher, all of the above,....).
Voicemeeter is not that complex but it is extremely flexible and gives you the power to decide what goes where.
The only issue so far, is a slight delay/latency between playing and hearing the bass through the PC headphone out (no latency using the Helix headphone out) but I decide to still use so I'm able to sync my playing with the backing track.
It can be caused by a number of things. It can either be a config/settings issue, an Helix driver issue, or my PC not being able to cope (just a regular laptop).
I'm still looking into it...
Be safe and have fun!
Cheers,
Pedro.