I had a similar issue with the web camera not showing in the device manager.  However, the issue was intermittent.  95% of the time Device Manager did not find the camera, 5% it did.  When it was recognized I followed instructions on the web to  update the driver.  No success.  Then tried unstalling the device followed by a reboot which automatically reinstalls the driver.  Again no success.  At one point the web cam intermittently work while running the Camera app.  This suggested the software driver was ok and maybe I was dealing with a hardware issue.  Found a video on YouTube showing how to remove the bezel on the laptop monitor.  Simply pull the inside of the bezel away from the screen and little hooks release.  This exposed the webcam board and the cable that connects to it.  Pushing the connector hard into the webcam board got the camera working continuously.  However, as soon as I let go the intermittent problem returned.  This suggested either a bad webcam board or cable connector.  Took a chance and bought a used Webcam Board 767N9 0767N9 on ebay for $8.  Could not find a new for short $$.  Swapped the hardware and the video camera is working consistently again.

option 1) take off cover of screen unplug and plug the cable webcam restart the pc and done.

This hapen to me in 2 m4800

option 2) go to setup and see the camera is enable cheked

Open the screen case and replug the cable in the webcam center in the screen up is a white conector small they have a false contact...

Well ensure it's not hidden and that the camera isn't disabled. If that isn't the case, install camera drivers manually, reset the camera, run the camera troubleshooter, and run Windows built-in scans.