title: Connect to multiple Firebase DB
body: <p>My flutter app needs to connect to multiple firebase databases. the vision is that the user will start the application and will enter Firebase parameters and click "Connect".
  I find the following source lines</p>
  
  <pre><code>FirebaseApp app;
    Future&lt;FirebaseApp&gt; FBDB() async {
      WidgetsFlutterBinding.ensureInitialized();
      final FirebaseApp app = await FirebaseApp.configure(
        name: "FB.AAA.com", // "package_name"
        options: const FirebaseOptions(
          googleAppID: "1:79046:android:2fb2895a41bde78da062d",
          // "mobilesdk_app_id"
          gcmSenderID: "???",
          //"project_number":
          apiKey: "AIzamVHoX0C_zimD3UhUITF4ml7Be4fsI",
          //  "api_key": [ { "current_key"
          projectID: "fb-b64d", //"project_id"
        ),
      );
    }
  </code></pre>
  
  <p>The Google Services file is (changed the data):</p>
  
  <pre><code>{
    "project_info": {
      "project_number": "123",
      "firebase_url": "https://fb-b64d.firebaseio.com",
      "project_id": "fb-b64d",
      "storage_bucket": "fb-b64d.appspot.com"
    },
    "client": [
      {
        "client_info": {
          "mobilesdk_app_id": "1:79046:android:2fb2895a41bde78da062d",
          "android_client_info": {
            "package_name": "FB.AAA.com"
          }
        },
        "oauth_client": [
          {
            "client_id": "123-5555.apps.googleusercontent.com",
            "client_type": 3
          }
        ],
        "api_key": [
          {
            "current_key": "AIzamVHoX0C_zimD3UhUITF4ml7Be4fsI"
          }
        ],
        "services": {
          "appinvite_service": {
            "other_platform_oauth_client": [
              {
                "client_id": "793081656-5555.apps.googleusercontent.com",
                "client_type": 3
              }
            ]
          }
        }
      }
    ],
    "configuration_version": "1"
  }
  </code></pre>
  
  <p>The result of the source code above is null (the object was not created) so my questions are:</p>
  
  <ol>
  <li><p>Did I take the right parameters from the google Json file to the source code above? what should be in the gcmSenderID?</p></li>
  <li><p>what is the next step? how should I receive the </p>
  
  <pre><code>final FirebaseAuth _firebaseAuth = FirebaseAuth.instance
  </code></pre>
  
  <p>In order to start query the DB?</p></li>
  </ol>