Autocast for Diablo 3 on any Mac made easy

Is that really true?
Just wanted to share as I found a lot of people asking about the Mac version. PC-gamers have their Numlock.
If it’s so than please delete the post. I hope it’s not.

EDIT: I looked through the Forum Code of Conduct and did not find anything against this.
Just hope I’m providing some technical support for the Mac community. If not I accept the thread being deleted.