I have a 2019 Macbook Pro 16 inch, one personal, one for work. I use the webcam cover slides from imluckies:
https://www.amazon.com/imluckies-Ul...ld=1&keywords=imluckies&qid=1593112969&sr=8-2
I installed them with the right side over the webcam; I slide the cover to the right to cover the webcam. Both the LED and the Ambient Light Sensor are to the right of the webcam.
This device is really thin, and small. My mindset was to install it this way to avoid covering the webcam LED. And I didn't even think about where the Ambient light sensor was until much, much later. I wasn't sure if I had covered the Ambient light sensor, and I could not find a layout diagram. But I figured it out with a simple test:
1) Bring up Displays in System Preferences
2) On the Display tab, set Brightness to a low setting, and enable "Automatically adjust brightness"
3) Use your phone's LED, and align along the screen's top bezel, and keep it as close to the screen as you can. Run it from left to right along the screen bezel. The closer you keep your phone's LED to the screen, to more accurate your response. As you pass the webcam's LED, the Brightness slider (and the brightness of your screen of course) will increase, and as you camp out over the Ambient Light Sensor the brightness should approach the slider's maximum, and drop back down as you move further away from the sensor.
My company uses the Google Office suite, and thus Google Hangouts/Meet. With Google Meet, you have the option to mute yourself and mute your webcam before entering a meeting, but it's easy enough to accidently hit the webcam mute button. So whether someone can view me without the webcam LED coming on, doesn't matter, I'm more concerned with accidently enabling my webcam during a meeting, especially when working from home. ;-)