Here is a simple mount I use for my Logitech C310 webcam on my Ender 3.

This mount require 1 (or more If needed) 8mm rod. This allow to the Webcam to be far enough from the print and get a good view, but not too far to save some space. Mine is 130mm to get a good view.

You'll need all the parts for the complete mount. You can reuse parts to make a 2 rods mount, which will extend the mount. I didn't do it, but it's possible.

The base is mounted on the X Axis stepper motor mount, which is pretty nice because this way, the camera will "follow" the nozzle.

Unfortunately the stock screws for the stepper motor mount are very short so you'll need 2 M3 * 45mm screws.
Also are need 4 M3 * 14mm screws and there hex nuts to fasten the different joints.

Finally, I strongly recommend the Logitech C270/C310 Focus Ring because I don't think that you will have a good focus without it.

Enjoy !