Unity calls the phone camera to identify the QR code

using ;
using UnityEngine;
using ZXing;
 
public class WebCameraScript : MonoBehaviour
{
 public string LastResult;
 public string Lastresult;
 public Color32[] data;
 private bool isQuit;
 
 public GUITexture myCameraTexture;
 private WebCamTexture webCameraTexture;
 
 private void Start()
 {
 // bool success = (.FOCUS_MODE_CONTINUOUSAUTO);
 // Checks how many and which cameras are available on the device
 for (int cameraIndex = 0; cameraIndex < ; cameraIndex++)
 {
  // We want the back camera
  if (![cameraIndex].isFrontFacing)
  {
  //webCameraTexture = new WebCamTexture(cameraIndex, , );
  webCameraTexture = new WebCamTexture(cameraIndex, 200, 200);
 
  // Here we flip the GuiTexture by applying a localScale transformation
  // works only in Landscape mode
   = new Vector3(1, 1, 1);
  }
 }
 
 // Here we tell that the texture of coming from the camera should be applied 
 // to our GUITexture. As we have flipped it before the camera preview will have the 
 // correct orientation
  = webCameraTexture;
 // Starts the camera
 ();
 //enabled=
 }
 
 public void ShowCamera()
 {
  = true;
 ();
 }
 
 public void HideCamera()
 {
  = false;
 ();
 }
 
 private void OnGUI()
 {
 (new Rect(60, 30*1, , 20), "LastResult:" + LastResult);
 if ((new Rect(0, 0, 100, 100), "ON/OFF"))
 {
  if ()
  HideCamera();
  else
  ShowCamera();
 }
 }
 
 private void Update()
 {
 //data = new Color32[ * ];
 data = webCameraTexture.GetPixels32();
 
 DecodeQR(, );
 }
 
 
 private void DecodeQR(int W, int H)
 {
 if (isQuit)
  return;
 // create a reader with a custom luminance source
 var barcodeReader = new BarcodeReader {AutoRotate = true, TryHarder = true};
 
 // while (true)
 {
  try
  {
  // decode the current frame
  Result result = (data, W, H);
  if (result != null)
  {
   LastResult = ;
   // shouldEncodeNow = true;
   print("i read out::" + );
  }
 
  // Sleep a little bit and set the signal to get the next frame
  (200);
  data = null;
  }
  catch
  {
  }
 }
 }
}