Thank you for your reply, I've already seen the Topic on the Forum.
The "Instructions" are not that detailed. They are using a sensor called "Tunnel", which does a little bit more than detect outage of Filament. It also detects filament movement, it's connected to J23, which consists of 3 Pins(PC7, +5V, GND).
So can I even connect a mechanical switch without electronics? Do i need an NO-Switch instead of my NC? Do I need something fancy like a Drop-Down-Resistor(like this)
Sadly, i still don't understand how to realise that function.