i'm trying to make the packed atlas and use the reacts to get the width and height then apply it to the material how do you do it

keep getting error Array size must be at least width*height? how do you fix it Runtime error

     public Texture2D[] atlasTextures;
     public Rect[] rects;
     public Texture2D atla;
 
     void Start() {
         Texture2D atlas = new Texture2D(8192, 8192);
         rects = atlas.PackTextures(atlasTextures, 2, 8192);
         
         atla = atlas;
         
         
         StartCoroutine(Example());
     }
     
      IEnumerator Example() {    
         for(int i=0 ; i<atlasTextures.Length; i++){
         int x = Mathf.FloorToInt(rects[i].x);
         int y = Mathf.FloorToInt(rects[i].x);
         int width = Mathf.FloorToInt(rects[i].width);
         int height = Mathf.FloorToInt(rects[i].height);
             
         Color[] pix = atla.GetPixels(x, y, width, height);
         Texture2D destTex = new Texture2D(width, height,TextureFormat.ARGB32,false);
                 destTex = atla;
         destTex.SetPixels(pix);
         destTex.Apply();
         renderer.material.mainTexture = destTex;
             yield return new WaitForSeconds(0.5f);
     }
 }