Augmented Reality-how to correct the right rotation of the 3d model when being tracked on its marker

Hi, I'm new in using unity and vuforia.

As you can see in the image, when being tracked, the 3D model is in incorrect rotation (picture 1). So i decided to untick the Adjust Shoplot (script). when i tested it again, the 3D model is in correct rotation when being tracked (picture 2). The Adjust Shoplot (script) is about rotating and scaling the 3D model using slider. So i think, i need to fix somewhere in the script so that the 3D model is in correct rotation as i wanted in picture 2.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class AdjustShoplot : MonoBehaviour
 {
     public float rotationMin = 0.0f;
     public float rotationMax = 45.0f;
     public Slider RotateSlider;
     public Slider ScaleSlider;
 
     [SerializeField] float currentRotation = 0f;
     [SerializeField] float currentScale = 0.1f;
     // Use this for initialization
 
     // Start is called before the first frame update
     void Start()
     {
         RotateSlider = GameObject.Find("RotateSlider").GetComponent<Slider>();
         ScaleSlider = GameObject.Find("ScaleSlider").GetComponent<Slider>();
     }
 
     // Update is called once per frame
     void Update()
     {
         transform.localEulerAngles = new Vector3(0.0f, RotateSlider.value, 0.0f);
         transform.localScale = new Vector3(ScaleSlider.value, ScaleSlider.value, ScaleSlider.value);
     }
     private void OnGUI()
     {
         currentRotation = GUI.HorizontalSlider(new Rect(-280f, 165.0f, 228.0f, 57.0f), currentRotation, 0.0f, 45.0f);
         transform.localEulerAngles = new Vector3(0.0f, currentRotation, 0.0f);
         currentRotation = GUI.HorizontalSlider(new Rect(-280f, 165.0f, 228.0f, 57.0f), currentScale, 0.0f, 2f);
         transform.localScale = new Vector3(currentScale, currentScale, currentScale);
     }
     public void AdjustAngle(float newAngle)
     { }
     public void AdjustScale(float newscale)
     { }
 }
 

it is actually based on this tutorial https://www.youtube.com/watch?v=uxgF9DkRYLM&t=490s. Also it would be very kind if someone can explain the coding attached & also is it probably i need to change the currentRotation value?