Firebase Push Notifications not being received by SwiftUI app

Question

I have become completely confused regarding what is required in order to receive push notifications from Firebase. I have the following in my app delegate - please could someone help me? I have set up a server script that should trigger the notifications - but I have been testing it using the Firebase test message page and have had no luck.

I have been using the fem token - but I also see a Device push notification token - is that for if I want to send messages/notifications from my app?

class AppDelegate: UIResponder, UIApplicationDelegate
{
    var window: UIWindow?
    let gcmMessageIDKey = "gcm.message_id"
    @AppStorage("fcm") var fcm: String = ""
    
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication
                        .LaunchOptionsKey: Any]?) -> Bool
    {
        UNUserNotificationCenter.current().delegate = self
        FirebaseApp.configure()
        
        // [START set_messaging_delegate]
        //FirebaseApp.configure()
        Messaging.messaging().delegate = self
        // [END set_messaging_delegate]
        
        // Register for remote notifications. This shows a permission dialog on first run, to
        // show the dialog at a more appropriate time move this registration accordingly.
        // [START register_for_notifications]
        
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { granted, error in
            if granted {
                DispatchQueue.main.async {
                    UIApplication.shared.registerForRemoteNotifications()
                }
            }
        }
        
        application.registerForRemoteNotifications()
        
        // [END register_for_notifications]
        return true
    }
    
    func application(_ application: UIApplication,
                     didReceiveRemoteNotification userInfo: [AnyHashable: Any]) {
        // If you are receiving a notification message while your app is in the background,
        // this callback will not be fired till the user taps on the notification launching the application.
        // TODO: Handle data of notification
        
        // With swizzling disabled you must let Messaging know about the message, for Analytics
        Messaging.messaging().appDidReceiveMessage(userInfo)
        
        // Print message ID.
        if let messageID = userInfo[gcmMessageIDKey] {
            print("Message ID: \(messageID)")
        }
        // Print full message.
        print(userInfo)
    }
    
    // [START receive_message]
    func application(_ application: UIApplication,
                     didReceiveRemoteNotification userInfo: [AnyHashable: Any]) async
    -> UIBackgroundFetchResult {
        // If you are receiving a notification message while your app is in the background,
        // this callback will not be fired till the user taps on the notification launching the application.
        // TODO: Handle data of notification
        
        // With swizzling disabled you must let Messaging know about the message, for Analytics
        Messaging.messaging().appDidReceiveMessage(userInfo)
        
        // Print message ID.
        if let messageID = userInfo[gcmMessageIDKey] {
            print("Message ID: \(messageID)")
        }
        
        // Print full message.
        print(userInfo)
        
        return UIBackgroundFetchResult.newData
    }
    
    // [END receive_message]
    
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        // Convert token to string and send to your server
        let tokenString = deviceToken.map { String(format: "%02.2hhx", $0) }.joined()
        print("Device push notification token: \(tokenString)")
        // Here you would typically send the token to your server
    }
    
    func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
        print("Failed to register for remote notifications: \(error)")
    }
    
    
    
    
}
    
// [START ios_10_message_handling]

extension AppDelegate: UNUserNotificationCenterDelegate {
  // Receive displayed notifications for iOS 10 devices.
  func userNotificationCenter(_ center: UNUserNotificationCenter,
                              willPresent notification: UNNotification) async
    -> UNNotificationPresentationOptions {
    let userInfo = notification.request.content.userInfo

    // With swizzling disabled you must let Messaging know about the message, for Analytics
    Messaging.messaging().appDidReceiveMessage(userInfo)

    // [START_EXCLUDE]
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
      print("Message ID: \(messageID)")
    }
    // [END_EXCLUDE]

    // Print full message.
    print(userInfo)

    // Change this to your preferred presentation option
        return [[.banner, .sound]]
  }
    

  func userNotificationCenter(_ center: UNUserNotificationCenter,
                              didReceive response: UNNotificationResponse) async {
    let userInfo = response.notification.request.content.userInfo

    // [START_EXCLUDE]
    // Print message ID.
    if let messageID = userInfo[gcmMessageIDKey] {
      print("Message ID: \(messageID)")
    }
    // [END_EXCLUDE]

    // With swizzling disabled you must let Messaging know about the message, for Analytics
    Messaging.messaging().appDidReceiveMessage(userInfo)
      NotificationHandler.shared.handle(notification: response)
    // Print full message.
    print(userInfo)
  }
}