Someone just pointed out to me that the simplest way to turn on the assistant menu, is via the settings option 'interaction and dexterity'; absolutely excellent information, and this method leaves the assistant menu on permanently on your screen, which I like.
The other method is to turn on the accessibility button, and then you can toggle the assistant menu on and off, whenever you like; and, therefore, have access to the screenshot button whenever you like.
They're both great options.
I solemnly promise, I will never speak of screenshots (or screen capture) again.
arrivederci 😀