Facetime while macbook pro in clamshell (with external webcam)

Hi,

A similar question was posed back in 2011 without a solution.

I have a 2011 macbook pro (with high sierra) running in clamshell mode while connected to my tv and receiver. I would like to use facetime with an external webcam and am wondering if there is a webcam that will be detected by OSX while in clamshell mode that will also be detected by Facetime.

Thanks