Is modify transform in OnStateUpdate function impossible?

I have been trying to create a state machine character controller.
And not even the simplest “characterController.transform.position += Vector3.forward” will take place.
I can move my character with characterController.Move(), I cant rotate him though.

I just want to confirm if it is impossible. If it is, I’ll be implementing my own state machine. (unwillingly)

According to the example script you can use

public class ExampleScript : StateMachineBehaviour
{
override public void OnStateUpdate(Animator animator, AnimatorStateInfo stateInfo, int layerIndex)
    {
        Debug.Log("On Attack Update ");
    }
} 

to have a custom OnStateUpdate