BigTreeTech mini e3 V1.2 endstop installation
You do not need to connect the red (+) wire of the endstops. The controller board uses a technique to ensure the signal is 3.3&nbsp;V or ground, see the top left schematics of this link (will insert an image later!). Specifics about this technology is found here and is explained as using a pull up resistor.

What happens is that the signal is always reported as triggered, unless the endstop connects the signal wire to ground.

This link shows that only ground and signal are required (will insert an image later!).