how to flip a sprite using touchpad input

Hi I'm new to game development and making my first game

A have been using the unity tutorials to help me a lot and came across an issue of how to flip my sprite when moving it in different direction.

The code from the tutorial was:

 MOBILE DEVELOPMENT: CONVERTING SPACE SHOOTER TO MOBILE
 BEGINNER LIVE TRAINING ARCHIVE
 To download the "Mobile Artwork" for this session please use the link [HERE].
 
 SimpleTouchPad
 
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 Copy codeC#
 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.EventSystems;
 using System.Collections;
 
 public class SimpleTouchPad : MonoBehaviour, IPointerDownHandler, IDragHandler, IPointerUpHandler {
 
     public float smoothing;
 
     private Vector2 origin;
     private Vector2 direction;
     private Vector2 smoothDirection;
     private bool touched;
     private int pointerID;
 
     void Awake () {
         direction = Vector2.zero;
         touched = false;
     }
 
     public void OnPointerDown (PointerEventData data) {
         if (!touched) {
             touched = true;
             pointerID = data.pointerId;
             origin = data.position;
         }
     }
 
     public void OnDrag (PointerEventData data) {
         if (data.pointerId == pointerID) {
             Vector2 currentPosition = data.position;
             Vector2 directionRaw = currentPosition - origin;
             direction = directionRaw.normalized;
         }
     }
 
     public void OnPointerUp (PointerEventData data) {
         if (data.pointerId == pointerID) {
             direction = Vector3.zero;
             touched = false;
         }
     }
 
     public Vector2 GetDirection () {
         smoothDirection = Vector2.MoveTowards (smoothDirection, direction, smoothing);
         return smoothDirection;
     }
 }

I'm just trying to figure out the best way to flip my sprite. Before implementing touch I used a if transform = -1 flip method but that doesn't seem to work

Any ideas?