Change the Z-endstop with another sensor

Hello everyone,

I want to install autobedlevelling on the Vertex 3D Printer for even more smoother prints.
As far as I know, the endstops are NC? But I can’t figure out what for a signal they gave…

I want to change the Z-endstop opto to a proximity sensor (NO)

Anybody who can help?

Cheers,
Dylan