Pulseaudio loopback: I can only see one input microphone

I'm currently recording a video with two microphones attached to my computer (OS: Ubuntu 20.10).

There's the microphone that I want to monitor (a USB podcasting mic) and the built-in microphone to my webcam that I don't need to monitor and is just part of the webcam.

When I open up Pulseaudio, I can see levels for both mics and use them to record etc.

However, when I load module-loopback I am only able to see a loopback playback output for one of the two microphones (which, unfortunately, is the webcam mic that I don't want to monitor).

If I disconnect the webcam then the loopback feels falls back automatically to the podcasting mic. But I need to record with the webcam and monitor with the podcasting mic - so this doesn't help me much.

Is there some way to get a separate loopback channel for each recording input so that I can listen to the one that I want to?

Thank you!