For example, how would you stream audio from software like Ableton Live or Garageband into the Vuo Receive audio node?
Answer: Use Soundflower to create an audio output device in the originating software and Soundflower will show up as an Audio Input in the Receive Live Audio node.
There’s also this https://rogueamoeba.com/loopback/
If audio and Vuo are not on the same computer, there’s also this https://www.audinate.com/products/software/dante-via and this https://www.audinate.com/products/software/dante-virtual-soundcard