title: unity ads not showing up
body: <p>i followed the official unity tutorial on how to put bannner ads on my game, i set everything up in the unity dashboard, and in the editor i see a rectangle that says the ad should be there, but when i build the game nothing shows up, here is my script:</p>
  <pre><code>using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
  using UnityEngine.Advertisements;
  
  public class bannerad : MonoBehaviour
  {
  
      bool testMode = false;
      public string gameId = &quot;******&quot; (my game id is here i just dot want to share it);
      // Start is called before the first frame update
      IEnumerator Start()
      {
          Advertisement.Initialize(gameId, testMode);
  
          while (!Advertisement.IsReady(&quot;Lost_Ad&quot;))
          {
              yield return null;
          }
          Advertisement.Banner.SetPosition(BannerPosition.BOTTOM_CENTER);
  
          Advertisement.Banner.Show(&quot;Lost_Ad&quot;); 
      }
  
  
  
  
  
  
  }
  </code></pre>
  <p>anyone knows what is the solution?</p>