If D would be pressed then it sets the rotation to X=0

It would be something like

 if (Input.GetKeyDown(KeyCode.D))
        {

//and here the rotation
        }

What have you tried so far?

something like

CharacterTransform.transform.Rotate(0, 0, 0);

it only adds the rotation it needs to set it to something

Rotate() is like “add the rotation”, not “replace it”.
In your case you need:

var euler = transform.eulerAngles;
euler.x = 0;
transform.eulerAngles = euler;

Thank u it worked! :slight_smile: