I used the mounting arm from the Blink Camera Holder here to mount to the Ender 3/Pro: https://www.thingiverse.com/thing:5526397

The bracket piece sits on top of this arm and connects with a M412 flat head screw, washer and nut. The camera mount connects to the bracket with the same size hardware and must be connected to the bracket before mounting the camera! For the camera module I used 4 x M212 flat head screws.

The holes on the camera mount should thread as you screw in the camera so no additional hardware is needed, but they can be secured with an M2 nut if desired. This is my first foray into my own design since I couldn't find a camera mount specifically for the Camera Module 3.

This is the exact camera module I'm using from Raspberry Pi (RSP-CAM-V3-WIDE): https://www.canakit.com/raspberry-pi-camera-module-3.html?cid=usd&src=raspberrypi