title: Invalid Network Credentials in Admob mediation process
body: <p>Entering Facebook App id and Access token throwing Invalid network credentials.
  For mediation I followed this Integration link <a href="https://developers.google.com/admob/ios/mediation/facebook" rel="nofollow noreferrer">https://developers.google.com/admob/ios/mediation/facebook</a>.</p>
  
  <p>As one of the steps, I don't find any apps to select in the list. Attaching the screenshot as shown in integration steps.</p>
  
  <p>I only doubt for Invalid network credentials by missing this step in my flow.
  <a href="https://i.stack.imgur.com/Fj8CK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Fj8CK.png" alt="I don&#39;t find apps in this list"></a></p>