In the IOS 13 documentation for CXProvider: reportNewIncomingCall () https://developer.apple.com/documentation/callkit/cxprovider/1930694-reportnewincomingcall
It says "An incoming call cannot be allowed by the system if, For example, the call handle is blocked, or the user does not disturb enabled. "
How is a call handle blocked? Does the handle block what the app itself can do?
(Note if a phone number is registered with the CallKit extension as blocked. This does not prevent the VoIP call screen from appearing when reportNewIncommingCall () is called, therefore I am wondering how the call handle is blocked)