Using an external webcam with iPad Pro

iPad Pro connects well to a BenQ monitor through usb but does not allow the webcam camera sitting on top of the monitor to work. It’s not convenient to use the iPad camera whilst using the iPad/monitor for video conferencing in this day and age, especially when you have a 27” monitor! Any suggestions please?

Perhaps Apple could offer a fix via the iPad ? Or is there an App that enables the webcam ?