Sometimes, when Apple updates your operating system, the camera permissions for chrome can change without warning. The result is that the camera cannot be activated by the BIGVU Teleprompter just like in the image here.
The camera might appear as an option, but this doesn't mean the permissions are enabled for Chrome on your Mac.
You can follow these steps to resolve the issue.
Step One: Go to System preferences
Step Two: Select Security and Privacy
Step Three: Enable camera permissions for Chrome