react-native-firebase notifications().onNotification() is never called in ios

I sent test messages from firebase console but firebase.notifications().onNitification((notification :Notification)=>{ console.log(notification); }) was never called.

The versions

- "react-native": "^0.61.2",
 - "react-native-firebase": "^5.5.6", 

podfile

 1. pod 'RNFirebase', :path => '../node_modules/react-native-firebase/ios'
 2. pod 'Firebase/Core', '~> 6.3.0'
 3. pod 'Firebase/Messaging', '~> 6.3.0'

What I did are...

1. I uploaded an APN key to the firebase project.

2. I put GoogleService-info.plist in my project.

3. Here is my AppDelegate.m

#import "AppDelegate.h"

#import <React/RCTBridge.h>
#import <React/RCTBundleURLProvider.h>
#import <React/RCTRootView.h>

#import <GoogleMaps/GoogleMaps.h>
#import <Firebase.h>
#import <FirebaseMessaging.h>
#import "RNFirebaseMessaging.h"
#import "RNFirebaseNotifications.h"
#import "RNSplashScreen.h"

@import Firebase;
@import UserNotifications;

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
  [FIRApp configure];
  [RNFirebaseNotifications configure];
  [GMSServices provideAPIKey:@""];
  RCTBridge *bridge = [[RCTBridge alloc] initWithDelegate:self launchOptions:launchOptions];
  RCTRootView *rootView = [[RCTRootView alloc] initWithBridge:bridge
                                                   moduleName:@""
                                            initialProperties:nil];

  rootView.backgroundColor = [[UIColor alloc] initWithRed:1.0f green:1.0f blue:1.0f alpha:1]; 
  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  UIViewController *rootViewController = [UIViewController new];
  rootViewController.view = rootView;
  self.window.rootViewController = rootViewController;
  [self.window makeKeyAndVisible]; 
  [RNSplashScreen show]; 
  return YES;
}

- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
  [[RNFirebaseNotifications instance] didReceiveLocalNotification:notification];
}

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(nonnull NSDictionary *)userInfo
fetchCompletionHandler:(nonnull void (^)(UIBackgroundFetchResult))completionHandler{
  [[RNFirebaseNotifications instance] didReceiveRemoteNotification:userInfo fetchCompletionHandler:completionHandler];
}

- (void)application:(UIApplication *)application didRegisterUserNotificationSettings:(UIUserNotificationSettings *)notificationSettings {
  [[RNFirebaseMessaging instance] didRegisterUserNotificationSettings:notificationSettings];
}

- (NSURL *)sourceURLForBridge:(RCTBridge *)bridge
{
#if DEBUG
  return [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index" fallbackResource:nil];
#else
  return [[NSBundle mainBundle] URLForResource:@"main" withExtension:@"jsbundle"];
#endif
}

@end

4. Here's my code

this.notificationListener = firebase.notifications().onNotification((notification: Notification) => {
    alert('in method')
    console.log("onNotification");
    console.log(notification);
    notification.setSound("default");
    notification.ios.setBadge(notification.ios.badge ? notification.ios.badge + 1 : 0);
    firebase.notifications().displayNotification(notification);
});