Shortcuts in general (undo) for using ipad as sidecar for Blender

I can use Blender on iPad via Sidecar - no problem with that on my MacBookPro.

Just the “handling” isn’t that clear to me.

e.g. For “undo” - do i really have to tap 2 times on the command button on the left side, then open keyboard and tap on z? This sounds a bit too complicated for me. Does anybody know a quicker way to undo in Blender on iPad/sidecar?