I'm using an application server to send messages by Firebase Cloud Messaging. Firebase console does not list such a message which sent by app server. When I use Firebase console directly to send messages, it will display some analysis on its own messages.
Like this:
The questions is, how can I access message statistics when I'm using an app servers?
As of August 2018 (announced in this blog post), API send stats can be viewed in the "Reports" tab of the FCM console. By default it only shows notification type messages, so if you're only sending data messages with the API, be sure to choose the "Data" filter.
Before August 2018:
The Firebase Notifications charts only show analytics for messages that were sent using the Firebase Notifications panel.
There is currently no public API to send Notifications to audiences. The web interface in the console is the only way to send them.
There is currently no API to feed your own FCM messages into the Firebase Notifications analytics panels.
来源：https://stackoverflow.com/questions/40124672/firebase-cloud-messaging-statistics-api