Sometimes, newly installed devices are not shown in the sources list.
Note: after any install/re-install of a virtual camera device, you must restart Chrome (and sometimes the computer).
Things to try:
Check if the camera shows in https://loola.tv/camtest
Check if the camera shows in https://hangouts.google.com (video call)
Check if the camera shows in other apps (Skype, OBS)
Restart the computer
Re-install the virtual camera software
Uninstall other virtual camera devices (sometimes there are device conflicts)
Google Chrome on macOS
Starting version 76.0.3809.87, Google Chrome has made a few changes that prevent Virtual Webcams (ManyCam, Ecamm Live, Wirecast, vMix and others) from appearing on the list of webcam options. The Google team have already confirmed the problem on their end and hopefully they will come up with an update soon.
In the meantime, we suggest using the Opera browser instead if you need to access to Virtual Camera on Mac.