npm i firebase now installs v9 Modular SDK so you cannot used the old imports. Try refactoring your code to this: import { initializeApp } from 'firebase/app'; const firebaseConfig = { //... }; const app = initializeApp(firebaseConfig); If you want to use older syntax then change your imports to compat libraries: import firebase from "firebase/compat/app" import "firebase/compat/auth" import "firebase/compat/firestore" // other services is needed You can read more about it in the documentation