1
If there is an image from the webcam, but the image is not correct, open the Settings App.
Go to Bluetooth an Devices - Cameras - Integrated Camera
In there, you will find some sliders to adjust the image on your webcam.
2
If that was not the problem.
Look at the camera lens above your screen, is there a small privacy slider that needs to be opened to access the webcam?
3
If that was not the problem, the best option is to go to the support page for your laptop on the manufacturers website to download and reinstall (not update) the version of webcam drivers they provide.
If you have any difficulty locating that support page, click your Start Button, then just type msinfo and press Enter, please provide a screenshot of the resulting System Information window.