add a camera to privacy settings

Hi MS10,

Welcome to the Apple Community.

Camera needs to be connected to show up in privacy settings, and app developers may provide access info.

Seems the settings for an external camera are mainly in the various apps that you want to use the camera.

Apple support have various articles online that may be helpful / useful.

Use an external camera with Mac:

https://support.apple.com/en-au/guide/mac-help/mchl034033f4/12.0/mac/12.0

Control access to the camera on Mac:

(NB: If there are no apps in the list, you haven’t installed an app that uses the camera.

FaceTime, Photo Booth and other apps that come with your Mac automatically have access — you don’t need to give them permission. 

AND 

In Safari, to allow a website to use the camera, choose Safari > Preferences, click Websites, then select Camera.)

Complete article: https://support.apple.com/en-au/guide/mac-help/mchlf6d108da/12.0/mac/12.0

Choose a camera or microphone for FaceTime calls on Mac

httphttps://support.apple.com/en-au/guide/home/hmeb54708fc8/mac

OR

Set up security cameras to use with Home on Mac

https://support.apple.com/en-au/guide/home/hmeb54708fc8/mac

Hope there is something useful; here :-)