The solution I found is what I have been using today. And guess what? In Riot, Firefox. Chrome, DIscord, etc. etc.I only have to switch to the MyPhone Camera and it works. AFAIK Epocam is for Apple devices. My bet is that IP webcam works kind of like Droid Cam, they stream the Camera image to a specific port through some small webserver. In both cases ffmpeg uses the v4l2loopback device ( which creates an entry in /dev/ and can be used like any /dev/video* device.
FYI You can test the functionality first, by browsing to the phone’s ip adres:4747