title: Flutter Firebase Authentication with Email Links not working
body: <p>I'm following <a href="https://firebase.google.com/docs/auth/flutter/email-link-auth" rel="nofollow noreferrer">this guide</a>, I'm having this code:</p>
  <pre><code>var acs = ActionCodeSettings(
    url: 'https://example.com/auth/widget',
    androidPackageName: 'com.example',
    iOSBundleId: 'com.example',
    handleCodeInApp: true,
    androidInstallApp: true,
    androidMinimumVersion: '12',
  );
  
  var emailAuth = 'john.doe@pm.me';
  FirebaseAuth.instance
      .sendSignInLinkToEmail(
          email: emailAuth, actionCodeSettings: acs)
      .catchError((onError, stackTrace) {})
      .then((value) =&gt;
          print('Successfully sent email verification'));
  </code></pre>
  <p>Sending the email works, but when I click on the email, then…</p>
  <ul>
  <li>in iOS it opens <a href="https://example.com/auth/widget" rel="nofollow noreferrer">https://example.com/auth/widget</a> - which is the fallback</li>
  <li>in Android it shows a circular loader for about 1s and then it &quot;falls down&quot; and nothing happens</li>
  </ul>
  <p>The incoming link handler</p>
  <pre><code>FirebaseDynamicLinks.instance.onLink.listen((dynamicLinkData) {
      print('got dynamic link! $dynamicLinkData');
  }).onError((error) {
      print('error error!');
  });
  </code></pre>
  <p>I configured dynamic links in Firebase to point to <code>to.example.com</code>. I also added a manual dynamic link <code>to.example.com/test</code> which opens my app (the <code>got dynamic link!</code> message shows up) - so all seems fine, the problem seems to lie in the link generation.</p>
  <p>The link structure I get by email is:</p>
  <p><code>https://to.example.com/?link=https://example-abcd.firebaseapp.com/__/auth/action?apiKey…%26continueUrl%3Dhttps://example.com/auth/widget%26lang%3Den&amp;apn=com.example&amp;amv=12&amp;ibi=com.example&amp;ifl=https://example-abcd.firebaseapp.com/__/auth/action?apiKey%3D…%26continueUrl%3Dhttps://example.com/auth/widget%26lang%3Den</code></p>