Push Notification does not working on first time installation - ios

Question

I am getting stuck on push notification. When I am installing the app first time then the firebase notification does not trigger, but after killing one and open again app it's working fine.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
// Use Firebase library to configure APIs
FirebaseApp.configure()
if #available(iOS 10.0, *) {
// For iOS 10 display notification (sent via APNS)
UNUserNotificationCenter.current().delegate = self
let authOptions: UNAuthorizationOptions = [.alert, .badge, .sound]
UNUserNotificationCenter.current().requestAuthorization(
options: authOptions,
completionHandler: {_, _ in })
} else {
let settings: UIUserNotificationSettings =
UIUserNotificationSettings(types: [.alert, .badge, .sound], categories: nil)
application.registerUserNotificationSettings(settings)
}
application.registerForRemoteNotifications()
Messaging.messaging().delegate = self
Messaging.messaging().isAutoInitEnabled = true
return true
}
func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String) {
print("Firebase registration token: \(String(describing: fcmToken))")
UserDefaults.standard.setValue(fcmToken, forKey: "Token")
let dataDict:[String: String] = ["token": fcmToken ]
NotificationCenter.default.post(name: Notification.Name("FCMToken"), object: nil, userInfo: dataDict)
// TODO: If necessary send token to application server.
// Note: This callback is fired at each app startup and whenever a new token is generated.
}
func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
Messaging.messaging().apnsToken = deviceToken
}
func application(_ application: UIApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
}