Automate whatspp calling on desktop (Mac)

Hi all

I wish to get a simple automation:

Pre-requisites:
- Run on the background (do not disturb using the mac for other purposes)
- Run on MacOS (latest version)
- Automate Whatsapp desktop app (not web version)
- Automate to make VIDEO CALLS (not messages)
- If your automation requires command lines I'll need detailed explanation on how to run it.
- If it requires installing packages, I'll need detailed explanation on how to do it and trouble-shooting too.

Here's what I need in detail:
1. I've one specific whatsapp number that is often busy
2. Once the automation is running I wanted it to start video calling the number and MUTE the MacOs system
3. If it hits a busy line, it should hang up and video call IMMEDIATELY after
4. If it rings or if the call is answered:
4.1 Mac OS Volume should go up to 70% (unmute)
4.2 The automation should stop running and allow the call to be run normally
4.3 Mac OS should focus (pop up) the Whatsapp video call window