Trying to use OBS Studio to stream video and audio on macOS Catalina?

You may have some problems until they make an officially supported release of the app, but you can get it working.

I had a problem getting the audio to be captured but this forum post helped solve it for me, the TL;DR is either download a test version of OBS, or run the app from the terminal with

open /Applications/OBS.app/Contents/MacOS/OBS --args -picture

Here is the forum post: https://obsproject.com/forum/threads/macos-10-15-catalina-support-status.111343/