update

ios/Runner/AppDelegate.swift

@@ -1,6 +1,7 @@
 import Flutter
 import UIKit
 import UserNotifications
+import Firebase
 
 @main
 @objc class AppDelegate: FlutterAppDelegate {
@@ -8,11 +9,18 @@ import UserNotifications
     _ application: UIApplication,
     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
+
+    FirebaseApp.configure()
+
     // Set notification delegate so notifications show in foreground & background
     UNUserNotificationCenter.current().delegate = self
 
     GeneratedPluginRegistrant.register(with: self)
-    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+
+    return super.application(
+      application,
+      didFinishLaunchingWithOptions: launchOptions
+    )
   }
 
   // Called when a notification is delivered while app is in foreground
@@ -24,7 +32,7 @@ import UserNotifications
     completionHandler([.banner, .badge, .sound])
   }
 
-  // Called when user taps a notification (foreground or background)
+  // Called when user taps a notification
   override func userNotificationCenter(
     _ center: UNUserNotificationCenter,
     didReceive response: UNNotificationResponse,
@@ -32,4 +40,4 @@ import UserNotifications
   ) {
     completionHandler()
   }
-}
+}