title: How to integrate LinkedIn authorization from OAuth.io with Firebase
body: <p>I am having trouble integrating LinkedIn authorization from OAuth .io with Firebase on Android.</p>
  
  <p>I am able to authenticate my user through LinkedIn, and OAuth .io is able to save the token into the Firebase database (on the application table not the system table, yet).</p>
  
  <p>But when I pass the received token to Firebase as shown on the code below, firebase replies with an error.</p>
  
  <pre><code>        oauth.popup("linkedin2", new OAuthCallback() {
          @Override
          public void onFinished(OAuthData data) {
              String token = data.token;
  
              FirebaseAuth.getInstance().signInWithCustomToken(token);
          }
  </code></pre>
  
  <p>The error I get is:</p>
  
  <blockquote>
    <p>com.google.firebase.auth.FirebaseAuthInvalidCredentialsException: The
    custom token format is incorrect. Please check the documentation.</p>
  </blockquote>
  
  <p>How can I make this work?</p>