I\'m using FCM to send notifications to Android devices. When the app is in background, if I send 10 notifications, the devices will show up 10 entries on the notification bar.<
To achieve this, in your notification payload, use the tag key
{ "notification" : { "title" : "Notification Title", "body" : "Notification Body", "tag" : "your_unique_tag" } }
Cheers.