Installation

config/firebase.js

const { getFirestore } = require("firebase-admin/firestore");
const { getMessaging } = require("firebase-admin/messaging");
var admin = require("firebase-admin");

const app = admin.initializeApp({
  credential: admin.credential.applicationDefault(),
  projectId: "XXX", // this line
  databaseURL: "XXX",
});

const db = getFirestore();
const messaging = getMessaging(app);

module.exports = { db, messaging };