I think this is what you're looking for. It's for High Sierra but I believe the same steps apply for Mojave and Catalina. The trick may be to NOT hit restart until you've ok'd the installation in the security panel. If you restart first my guess is that the extension is left in the sandbox - or whatever it's called in programming land.
This is a different issue from enabling the microphone thing...
https://www.youtube.com/watch?v=vsVd9kRgFo4