Load a sprite as a texture from.

This works

public Texture testTexture;

 void OnGUI() {
   GUI.DrawTexture(new Rect(0, 0, Screen.width, Screen.height), testTexture);
 }

I can drag and drop a texture, that works fine.

However I am trying to make it more dynamic.

So, I have a folder called resources, with a selection of PNG files (1.png, 2.png, 3.png...) I have set to sprites. The following does not work.

              Texture img = Resources.Load("1.png") as Texture;
             if (img) {
 
             GUI.DrawTexture(new Rect(0,0,Screen.width,Screen.height), productTexture);
             
             } 
 
             else {
 
             Debug.Log("Something bad happened, but I was prepared for that");
             
             }

Suggestions?