EpocCam not recognized by Zoom on new Mac

Bought a new Macbook and when I launch zoom it doesn't recognize my ipad's EpocCam.  Downloaded an EpocCam type alternative and that app sees my ipad but Zoom doesn't offer that connection as an alternative source either; when clicking on the video icon.   What switch haven't I clicked that I'm supposed to click?  Downloaded drivers and apps and everything I think I'm supposed to download to both ipad and Mac.... thanks for any thoughts.