Assistive touch on my iPad 2020 is not working.

I have assistive touch settings enabled on my 2020 iPad, but when getting to a screen that requires me to use Assistive Touch and I single click on the top button (not a volume button) nothing happens. Is there a way to confirm with face recognition or do I need to hold down the top button (portrait mode) longer.

I’m getting frustrated and I’m not a newbie!