Question
In which version, Godot Engine, does augmented reality be implemented for the first time?
augmented reality depends on access to a physical camera, this is by the CameraServer — Godot Engine (stable) documentation in English
this is only supported on macOS and iOS
then you can take that feed and put images and buttons on top of it.
so really I would say Augmented reality is not really yet supported out of the box but can be done in a limited way.