What Bearer token should I be using for Firebase Cloud Messaging testing?

Question

I am trying to send a test notification using Firebase Cloud Messaging via Postman. I'm doing a POST to this url

https://fcm.googleapis.com/v1/projects/[my project name]/messages:send 

The Authorization tab in Postman is set to No Auth and my Headers tab looks like this

Content-Type: application/json Authorization: Bearer [server key] 

[server key] is a newly generated server key in the 'Cloud Messaging' tab of my Firebase project's 'Settings' area. I keep getting this error in response.

"error": {     "code": 401,     "message": "Request had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.",     "status": "UNAUTHENTICATED" } 

Based on everything I can find, I'm using the right token, but it seems Google disagrees. What should I be sending as the Authorization header to get past this error?

Answer 1

Steps to get Authentication Bearer:

1. Got to Google OAuth Playground: https://developers.google.com/oauthplayground
2. In the "Input your own scopes" for FCM use this url: https://www.googleapis.com/auth/firebase.messaging
3. Tap Authorize API.
4. Pick correct user for authorisation and allow access.
5. In the Step 2: Exchange authorization code for tokens tap Exchange authorisation code for tokens.
6. Access token is your Bearer.

Steps to send FCM throw Postman:

1. URL to send: https://fcm.googleapis.com/v1/projects/projectid-34543/messages:send
2. Request Type: POST
3. Headers: Content-Type -> application/json & Authorization -> Bearer
4. In the body section enter APS payload with the right device token.
5. Click send.

In case you want to use cURL, for a data-notification:

curl --location --request POST 'https://fcm.googleapis.com/v1/projects/your-project-id/messages:send' \ --header 'Content-Type: application/json' \ --header 'Authorization: Bearer your-access-token-*****-wqewe' \ --data-raw '{     "message": {         "token": "device-token-qwfqwee-***-qefwe",         "data": {             "Key1": "val1",             "Key2": "val2"         }     } }'