...
Lenovo X390 Yoga
Lenovo Thinkpad T490s
Lenovo ThinkPad X13 Yoga (all models)
Lenovo ThinkPad T14s (all models)
When the camera shutter is closed there should be a red/black colored dot within the camera physically.
Below are photos of a Lenovo device with the shutter open and closed:
...
Shutter Open
...
Shutter Closed
...
...
To operate the shutter (i.e. move from open to closed and vice versa), slide the small switch located directly above the camera will be a small sliding switch.lens. Sliding the switch will open or close the camera depending on which way the switch is slid. When the camera shutter is closed there will be a red colored dot displayed over the camera lens.