private void Start()
{
PlayerInput playerInput = GameObject.FindGameObjectWithTag("Player").GetComponent <PlayerInput>();
playerInput.AddKeyCallback(KeyCode.W, MoveForward);
playerInput.AddKeyCallback(KeyCode.S, MoveBackward);
playerInput.AddKeyCallback(KeyCode.D, MoveRight);
playerInput.AddKeyCallback(KeyCode.A, MoveLeft);
}