Video mode - show picture instead when video on during meeting

I have a camera cover on my mac, and when I join a ringcentral meeting and switch on the video it shows green because of the cover. Instead I would like to show my name ..... I have to switch on the video in order to be able to see other participants and screenshare. How can I make this chnage so that when I select video on ringcentral meeting it does not show green for me, and instead shows my name