Stream Deck and KM still not working for me

I'm on Big Sur and I can't assign a button from my Stream Deck to a macro in KM.
I select the trigger: USB Device key trigger and the blue field with "none" appears. When I click one time in the blue field it will show "USB Receiver button 1", and immediately the macro will begin to run, causing all kind of trouble. So now I've learned to switch on debugging. If I click a 3rd time on the field and hit the smal "erase" cross to the right the field will now show "click", and when I do it will show Press and Release, so I'll press the button on my Stream Deck, and NOTHING happens, but that the button on the Stream Deck will have a yellow triangle with an exclamation mark.
What did fail to see here? How can I get this to work?

Did you install the Keyboard Maestro action in your StreamDeck settings? After it is installed, drag it to the StreamDeck key you are trying to assign. After you do that, go to Keyboard Maestro and choose that as a Device Key trigger in your first step.