Can't activate webcam on Ubuntu (18.04.5 LTS)

Question

I have installed the cheese software in order to activate the integrated webcam on my HP laptop. I get the message: No device found. I tried every solution that I found proposed on the Internet. Nothing worked. After typing the command lsusb, I got the following:

   Bus 002 Device 004: ID 8086:0189 Intel Corp. 
   Bus 002 Device 003: ID 093a:2510 Pixart Imaging, Inc. Optical Mouse
   Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
   Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
   Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
   Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
   Bus 001 Device 003: ID 138a:0018 Validity Sensors, Inc. Fingerprint scanner
   Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
   Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

The output of dmesg| grep -i cam is

[ 0.000000] AMD AuthenticAMD

For the permissions, ls -l /dev/video, I get:

ls: cannot access '/dev/video': No such file or directory

Typing in sudo adduser $USER $(stat --format="%G" /dev/video) I get a similar answer:

stat: cannot stat '/dev/video': No such file or directory adduser: The user `ibraim' already exists.

I also tried the following:

sudo apt-get update -y
sudo apt-get install -y webcam

Then checked with cheese to unfortunately only get the result:No device found.

Can somebody suggest what might go wrong in my case? Many thanks.