How can I get notification in iOS 10? In previous version, I can receive notification in     func application(application: UIApplication, didReceiveRemoteNotification user         
        
you have to move this method
application.registerForRemoteNotifications()
to above return statement.
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?)
-> Bool {
    FIRApp.configure()
    if #available(iOS 10.0, *) {
        let authOptions : UNAuthorizationOptions = [.Alert, .Badge, .Sound]
        UNUserNotificationCenter.currentNotificationCenter().requestAuthorizationWithOptions(
            authOptions,
            completionHandler: {_,_ in })
        // For iOS 10 display notification (sent via APNS)
        UNUserNotificationCenter.currentNotificationCenter().delegate = self
        // For iOS 10 data message (sent via FCM)
        FIRMessaging.messaging().remoteMessageDelegate = self
    } else {
        let settings: UIUserNotificationSettings =
            UIUserNotificationSettings(forTypes: [.Alert, .Badge, .Sound], categories: nil)
        application.registerUserNotificationSettings(settings)        
    }
    application.registerForRemoteNotifications()
   NotificationCenter.default.addObserver(self,
                                           selector: #selector(self.tokenRefreshNotification),
                                           name: .firInstanceIDTokenRefresh,
                                           object: nil)
    return true
 }