This can be done using a third-party iOS app. A product that we recommend is EpocCam by Kinoni. To use this:
- On your iOS device, install the EpocCam (free) or EpocCam HD ($7.99) from the iOS App Store. (EpocCam HD offer higher resolution and some other nice features.)
- Install both the drivers for macOS 10.12 and later and EpocCam Viewer Pro for Mac OS on the Mac. Both downloads are at the bottom of the page here.
- Run the app on the phone and the EpocCam Viewer Pro app on the Mac. You should see the camera's video coming through after a few seconds.
- In Ecamm Live, you should now see it offered as a camera source in the Camera menu and live camera switcher.
If troubleshooting is required, visit Kinoni's Mac support page.