Can't capture video when the project deployed to Android

Following the instructions form Playing Live Video Captures, I can get the correct result on windows(I used droidCam to connect my phone’s rear camera as a webcam). But when I deploy it on my android phone, the texture is just black and no response at all. I try to print the webcam URL, but the URL’s string is empty therefore nothing can be displayed. Can someone help me to solve this?

Just enable the “Android Camera Player” plugin, that’s ALL!!! Why the official doc didn’t mention this step, OMG!!!