Unable to send data message using firebase console

The Firebase Notifications Console can only be used to send notification messages. It cannot be used to send data messages.

See the table in message types in the Firebase documentation:

Notification message

Use scenario: FCM automatically displays the message to end-user devices on behalf of the client app. Notification messages have a predefined set of user-visible keys.

How to send:

1. Use your app server and FCM server API: Set the notification key. May have optional data payload. Always collapsible.

2. Use the Notifications console: Enter the Message Text, Title, etc., and send. Add optional data payload by providing Custom data in the Notifications console. Always collapsible.

Data message

Use scenario: Client app is responsible for processing data messages. Data messages have only custom key-value pairs.

How to send:

• Use your app server and FCM server API: Set the data key only. Can be either collapsible or non-collapsible.

Please look here: Firebase push notifications update DB, my post from June.

In conclusion, you need send HTTP POST request to https://fcm.googleapis.com/fcm/send

https://fcm.googleapis.com/fcm/send
Content-Type:application/json
Authorization:key=AIzaSyZ-1u...0GBYzPu7Udno5aA

{ "data": {
"score": "5x1",
"time": "15:10"
},
  "to" : "bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1..."
}

You can test both notification message and data message using Postman(rest client for testing http request).See screen shots:

In header pass:

key:Content-Type, value:application/json
key:Authorization:key=<Server key>