How to do crouching?

I’m trying to do it by shrinking he charactor controller height and camera’s position but i don’t know how to access these properties through code , any help ?

Here are the docs for accessing scene objects https://docs.flaxengine.com/manual/scripting/scene-objects.html?tabs=code-csharp. In your case if the Script is on your CharacterController, you can do something like var controller = Actor.As<CharacterController>() to get the CharacterController and then use standard c# to get the fields/properties.