Webcam covers & 3 holes/circles on front of iPhone 13 pro max

Hi everyone...Recently I noticed that there are 3 holes or circles to the right of the front facing camera on my iPhone 13 pro max. You can only see them in bright light like a flashlight. Does anyone know what they are for? I am going to put a webcam cover (toggle switch) over the camera but dont want to cover some sensor up.

thanks!