Google Admobs

Hi,

For some time now I’ve been struggling to put google admobs for my game.
I have followed this tutorial from googles official site : Mobile Ads SDK  |  Google for Developers

  1. I have imported the googleMobileAds.unitypackage
  2. I’ve added google-play-services_lib/ folder into Assets/Plugins/Android folder
  3. I’ve created my ad-unit-id from admobs
  4. I’ve added my ad-unity-id to my script
  5. I’ve attached my script to my main camera

When I build the app to my phone nothing shows up.
Can anyone help?

Thanks

anyone?