Multiple push notifications received

Recently I switched my application to production mode for push notification.
Then I scheduled the first notification through the dashboard and it worked well.

However, I received the same push notification 9 times. It never happened when I used development mode.
Should I register for push notification only once, or every time the application starts?

This is the code that executes every time the application starts.

  var user = $ionicUser.get();
  if (!user.user_id) {
    $ionicUser.identifyAnonymous().then(function() {
  } else {
    $ionicUser.identify(user).then(function() {
  function registerForPushNotification() {
      canShowAlert: true,
      canSetBadge: false,
      canPlaySound: true,
      canRunActionsOnWake: true,
      onNotification: function(notification) {

Now I’m afraid to try it again since my users may experience the same thing.

hello dear have you resolve this? im experience the same issue