Connect webcam to laptop?

So I have a video camera that also serves as a webcam.

I connected it to the laptop with a cable and that works too. So my laptop recognizes the webcam and also uses the video camera as a sound source (i.e. The sound is recorded by the camera) but the video does not work. My camera is the "Zoom Q8", a really good video camera.

Do you know how I get connected?

https://semo.edu/it/guides/pdf/campus_tech/ZoomQ8WebcamGuide.pdf

Instructions if you did it like this, check the cable what you are using, there are different USB cables with the one is not possible and the other should not, there are differences, I can't write you exactly

I did exactly that, it doesn't work