FCM - connected NodeJS, I'm getting this error "code": "app/invalid-credential"

Question

I'm trying to FCM push notification through to Nodejs

No code changes in this below code but today I'm getting error but yesterday it's worked perfectly.

Error from FCM :-

    "code": "app/invalid-credential",
    "message": "Credential implementation provided to initializeApp() via the \"credential\" property failed to fetch a valid Google OAuth2 access token with the following error: \"Error fetching access token: Error while making request: getaddrinfo ENOTFOUND metadata.google.internal. Error code: ENOTFOUND\"."
}

Code :-

import { initializeApp, applicationDefault } from "firebase-admin/app";
import { getMessaging } from "firebase-admin/messaging";

initializeApp({
  credential: applicationDefault(),
  projectId: "ecfile-test",
});

app.post("/send", function (req, res) {
  const receivedToken = req.body.fcmToken;

  const message = {
    notification: {
      title: "Notif",
      body: "This is a Test Notification",
    },
    token:
      "mytoken",
  };

  getMessaging()
    .send(message)
    .then((response) => {
      res.status(200).json({
        message: "Successfully sent message",
        token: receivedToken,
      });
      console.log("Successfully sent message:", response);
    })
    .catch((error) => {
      res.status(400);
      res.send(error);
      console.log("Error sending message:", error);
    });
});

Answer 1

You need to call initialiseApp passing a valid service account JSON instead of default credentials. Read about making a service account here

import * as admin from 'firebase-admin'
import * as creds from './path-to-service-account-key.json'


initializeApp({
  credential: admin.credential.cert({...creds}),
  projectId: "ecfile-test",
});

The .json should look like this, but populated

{
  "type": "service_account",
  "project_id": "",
  "private_key_id": "",
  "private_key": "",
  "client_email": "",
  "client_id": "",
  "auth_uri": "",
  "token_uri": "",
  "auth_provider_x509_cert_url": "",
  "client_x509_cert_url": "
}