EventSystem.current.currentSelectedGameObject

void Update () {

    var move = Vector2.zero;

    if (Input.GetKey ("up")) move += Vector2.up;
    if (Input.GetKey ("down")) move += Vector2.down;
    if (Input.GetKey ("right")) move += Vector2.right;
    if (Input.GetKey ("left")) move += Vector2.left;
    
    var position = transform.position + move * Time.deltaTime;
    
    position.x = Mathf.Clamp(position.x, -6.6f, 6.6f);
    position.y = Mathf.Clamp(position.y, -4.9f, 4.9f);
  
    transform.position = position;
}

sprite = GetComponentInChildren<SpriteRenderer>();