CS0120: An object reference is required for the non-static field, method, or property 'PlayerControls.currentState'

                
                        PlayerController obj = new PlayerController();
 void OnTriggerEnter2D(Collider2D collider) {
     if (collider.tag == "Player")
     {
         Debug.Log("Player is Re-Fueling"); 
         obj.AddFuel(1);
     }