AR basics
Edited
Let’s make sure that you have a working webcam. Here's the simplest "Augmented Reality" program you can code.
Add this script to the Stage, and then press Play.
You should see yourself (or whatever your webcam is pointing at) on the Tynker Stage. Click Stop and keep coding.
Hint: If your web browser asks permission to record from the webcam, Allow it so that Tynker can take photos and record videos.