Some folks asked how we made it sound so “professional”, and so I’m sharing here how we do it.
Most importantly: get everyone to record their audio locally. Audacity is free and works perfectly for this. Make sure you test that you can’t hear each other’s sound in the mix. Start recording, make sure the right microphone is in use by tapping it and observing the wiggly lines and then get others to make noise and ensure you hear them but don’t see the wiggly lines on your side.