I tried to record video on my Dell G15 laptop using built-in camera. Unfortunately, by default it does not work. I tried Cheese and Webcamoid using several different settings. Cheese did not work with both built-in and external camera. Webcamoid worked with external camera only. Finally I decided to try OBS-STUDIO and still built-in camera was crashing this piece of software also.

To fix this problem you could try to disable AppArmor:

sudo systemctl stop apparmor.service
sudo systemctl disable apparmor.service

If it is the case, then you can try to find which AppArmor profile is responsible for blocking camera recording. For me, it was the case. Now I can record using built-in camera.