Taking and storing a screenshot locally to later load on UI canvas (all in WebGL)

Unity WebGL clients are unable to save files on a user's computer because it runs in a browser, but I still want to be able to store files, even if they are only stored in some kind of virtual environment (as in, not a file physically stored permanently in the user's HDD folder). I only need files to be accessible by pointing to a path, even if its virtual, in order to be able to use Braincloud's Upload File API that requires a path declaration like this: string localPath = "path/to/my/file.dat"; (Braincloud is an SDK provider) So I've made a screenshot script that stores a file in Application.persistentDataPath and a Load texture script but unfortunately, I'm unable to make it work.

Would love to get some help.

TakeScreenshot Script:

 using UnityEngine;
 using System.Collections;
 using System.Runtime.InteropServices;
 using System.IO;
 
 public class TakeScreenshot : MonoBehaviour {
 
     // Using this for initialization
     public void Screenshot () {
         StartCoroutine(UploadPNG());
     }
  
     IEnumerator UploadPNG() {
         // We should only read the screen after all rendering is complete
         yield return new WaitForEndOfFrame();
  
         // Create a texture the size of the screen, RGB24 format
         int width = Screen.width;
         int height = Screen.height;
         var tex = new Texture2D( width, height, TextureFormat.RGB24, false );
  
         // Read screen contents into the texture
         tex.ReadPixels( new Rect(0, 0, width, height), 0, 0 );
         tex.Apply();
         
          string file = Application.persistentDataPath+"/test.png";         
          var fileData = tex.EncodeToPNG();
          File.WriteAllBytes(file, fileData);
          StreamReader reader = new StreamReader(file); 
          Debug.Log(reader.ReadToEnd());
          reader.Close();
 
     }
 }      

 

LoadTexture Script:

 using UnityEngine;
 using UnityEngine.UI;
  
 public class LoadTexture : MonoBehaviour {
     Texture2D myTexture;
     // Using this for initialization
     public void LoadScreenshot() {
         // load texture from resource folder
         myTexture = Resources.Load (Application.persistentDataPath+"/test.png") as Texture2D;
         GameObject rawImage = GameObject.Find ("RawImage");
         rawImage.GetComponent<RawImage> ().texture = myTexture;
         Debug.Log ("Applied");
     }
 }