title: flutter how to show first an interstitial ad through button and then go to new screen?
body: <p>i want to load an interstitial ad with a button in flutter. I want to show first the interstitial and then, when ad finish, go automaticaly to another screen, or load another thing.</p>
  <p>I dont know how to make something like &quot;interstitial.wait&quot; to show first the ad, and when it will close run another thing.</p>
  <p>this is my code:</p>
  <pre><code>onPressed: () {
     showInterstitialAd(); //this first
     launch(urlCourse.text); //when ad closed, run this
  }
  </code></pre>