For those who cannot access their camera on laptop(galaxy book users).
I've had the exact same problem. It kept saying that I don't have any camera connected on my laptop.
I've tried how other people solved their problem, but it all didn't work.
There was nothing wrong with my privacy camera settings.
The problem was "Samsung Security". It was blocking my camera and microphone from working.
Here's a simple solution:
Type "Samsung Security" on your search bar.
It looks like this at first.
Then, go to "Block camera and mic" menu on the left.
If this option is enabled, switch it off.
Thats all.
Your camera should be working now.