Click to show info problem.... Need Help...

Hello, i want to make slide information when object in the AR clicked like this... :

So, i follow instruction and type code like this :

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class InfoKlik : MonoBehaviour {
 
     public Transform target1 ;
     public Texture gambar1,gambar2,gambar3 ;
     public string info1,info2,info3;
     public Vector2 scrollposition1 = Vector2.zero;
     public bool show = false;
 
     void update() {
         if(Input.GetMouseButton(0)) {
             Ray ray = Camera.main.ScreenPointToRay (Input.mousePosition);
             RaycastHit hit;
 
             if(Physics.Raycast(ray, out hit)) {
                 if(hit.transform == target1) {
                     show=true;
                 }
             }
         }
     }
 
 
     void OnGui () {
         if(show==true) {
             GUI.BeginGroup (new Rect (Screen.width / 2 - 200, Screen.height / 2 - 250, 800, 500));
             GUI.Box (new Rect (0, 50, 405, 360), "informasi");
 
             scrollposition1 = GUI.BeginScrollView(new Rect(30,0,350,390),scrollposition1,new Rect(0,0,1150,200));
 
             GUI.DrawTexture (new Rect(0,90,350,210),gambar1);
             info1 = GUI.TextArea(new Rect(0,300,350,50),info1,200);
 
             GUI.DrawTexture (new Rect(400,90,350,210),gambar2);
             info2 = GUI.TextArea(new Rect(400,300,350,50),info2,200);
 
             GUI.DrawTexture (new Rect(800,90,350,210),gambar3);
             info3 = GUI.TextArea(new Rect(800,300,350,50),info3,200);
 
             GUI.EndScrollView();
             GUI.EndGroup();
 
         }
     }
 
 
 
 
 }
 
 

And i drag that code to ARCamera the result is :

I insert Target 1 my 3d model but when running i klick on the model it dIdn't show information box, Why?