iOS FCM Push notification is not receiving at the first run app - ios

Question

I build and test an app that uses FCM, but when I run the app for the first time, I don't get a push notification. But from the second run, notifications start to come.
The procedure for the application to send the token to the server is as follows.
The application is launched.
Store the token in UserDefault.
Get informed consent.
Proceed to membership registration.
At the end of membership registration, member information and token are sent together.
Membership registration completed
As a result of the test, the situation in which notifications do not come from the app is as follows.
Run the app for the first time and proceed with membership registration. = No notification.
Run the application for the first time to complete membership registration and turn off and on the application. = A notification is coming.
Turn the application off and on several times and proceed with membership registration. = No notification.
Turn the application off and on several times, sign up for a membership, and turn the application off and on. = Notification is coming.
If i enter the home screen without a push notification, I get a notification, but the didReceive function is not executed when I touch it.
Even if the terminal is turned off and on several times, the token is sent once when registering as a member, but I really don't know why these results are coming out.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
FirebaseApp.configure()
// 앱 메세지를 받는 델리게이트
UNUserNotificationCenter.current().delegate = self
Messaging.messaging().delegate = self
application.registerForRemoteNotifications()
return true
}
func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
messaging.token { token, _ in
guard let token = token else {
return
}
let defaults = UserDefaults.standard
defaults.set(token, forKey:"userFCMToken")
print("FIR Token : ", token)
}
}
The part of the AppDelegate that receives the FCM token. The part to receive notification consent from the user is to press a button in another ViewController.
UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound, .badge]) { success, _ in
guard success else {
print("알림 미동의")
self.registerViewPush()
return
}
print("알림 동의")
self.registerViewPush()
}
This is the part that receives notification consent when the button is pressed.
#available(iOS 10, *)
extension AppDelegate: UNUserNotificationCenterDelegate {
// Receive displayed notifications for iOS 10 devices.
// 어플 실행중일 때 화면에 보여주면서 실행
func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: #escaping (UNNotificationPresentationOptions) -> Void) {
print("willPresent App Push")
let userInfo = notification.request.content.userInfo
print("============willPresent================")
print(userInfo)
print("============================")
completionHandler([[.alert, .badge, .sound]])
}
// 사용자가 메세지를 눌렀을 때
func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: #escaping () -> Void) {
print("didReceive ")
let userInfo = response.notification.request.content.userInfo
print("============OriginaldidReceive================")
print(userInfo)
print("============================")
completionHandler()
}
}
The FirebaseMessaging I'm using is 9.0.0 and I installed it using a pod.
[
AnyHashable("google.c.fid"): f9lzDdLFjkQpneQsfb-GxW,
AnyHashable("google.c.sender.id"): 900007830000,
AnyHashable("type"): CRING,
AnyHashable("aps"): {
alert = {
body = "message";
title = "message";
};
sound = default;
},
AnyHashable("title"): message,
AnyHashable("google.c.a.e"): 1,
AnyHashable("push"): N,
AnyHashable("body"): message,
AnyHashable("gcm.message_id"): 1657080600087000
]
If this is successful, this is what I will receive.
It's okay if the answer isn't right. I'd appreciate it if you could let me know what I should check.

Answer 1

If you already have latest Firebase SDK version, then you properly missing registering for remote notifications as following:
UIApplication.shared.registerForRemoteNotifications()
after requesting authorization using
func requestAuthorization(options: UNAuthorizationOptions = []) async throws -> Bool
This was my mistake. I hope other developers find this answer helpful.