The endstop switch is attached to an endstop board. It's behind the Z lead screw such that the platform that is behind the Z lead screw will run into it when your platform moves upward.

I googled for an image of it in-situ. Most of the hits are for the shim people put on the platform when they add a glass bed (like me). I found this one of a broken Dreamer endstop: https://3dhubs.s3-eu-west-1.amazonaw...2-16-23-05.jpg It's similar, but the Creator Pro has a little metal tab instead of that red button.