How to set up Apple Pencil, iPad and MacBook Air with Sidecar

Hi.

I have an iPad Pro (6th gen.) that I would like to use as a graphics tablet while it's connected to my Mac. (Wireless or cable - doesn’t matter).

I draw in Pixelmator Pro on the Mac, but I need to use my Apple Pencil (2 gen.) when I work in details. That's where I want to use the iPad.

I've done before, but now I just can't get the setup to work again, and I've forgotten how I did it!

I use Sidecar to connect, and that part works, but there's no touch function, and the Pencil doesn't work either - ONLY the screen mirroring works.

It's a MacBook Air (M1) (OS 14.4), and the iPad is running iOS 17.4.

I hope someone understands my problem :-)

Does anyone have a fix?

[Re-Titled by Moderator]