How to record screen with the audio coming from your Mac? I'm trying to record my screen and the audio only coming from my Mac. 

When I do a screen recording with quicktime, with audio settings: internal microphone, it records the video but with a lot of external noise (like cats).

How do I make sure that the audio of what is being played on the screen (like music being played on my Mac) is recorded in the video file? 

I don't care if I'll have to record the screen and audio separately, or plug in earphones etc, I'd like to have a simple answer. 

I have already tried the suggestions in these other questions:


How to record both screen and sound with Quicktime?
How to record the sound also in a screen recording if the headphones are connected?
QuickTime Screen + Audio Capture


Sadly their solutions don't work for me, as my recordings still capture external noises on macOS Catalina.

What software or setup can do this?
Try using Background Music. 

When recording with Quicktime click the arrow and change the microphone to Background Music.


  You can record system audio with Background Music. With
  Background Music running, launch QuickTime Player and select File > New Audio Recording (or New Screen Recording, New Movie Recording). Then click the dropdown menu (⌄) next to the
  record button and select Background Music as the input device.
  
  You can record system audio and a microphone together by creating an
  aggregate device that
  combines your input device (usually Built-in Input) with the
  Background Music device. You can create the aggregate device using the Audio MIDI Setup utility under
  /Applications/Utilities.


Edit: If you have homebrew installed you can install using brew cask install background-music

source:https://github.com/kyleneideck/BackgroundMusic/blob/master/README.md