iPhone cam plus Mac Laptop

I used to be able to tie my iPhone X2 to my computer to use as an external camera for Zoom.  However, it's not showing up to select. The only cam that shows up is my internal Facetime camera. (lousey) Can you help, please?

Thanks.

SJ2

iPhone Xs

Software Version: 15.6.1

MacBook Pro

13' Late 2012

10.15.7