https://github.com/firebase/quickstart-js/tree/master/auth
<script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-app.js"></script> <script src="https://www.gstatic.com/firebasejs/7.6.1/firebase-auth.js"></script> <script> // コンソールの値を入れる! var firebaseConfig = { apiKey: "", authDomain: "", databaseURL: "", projectId: "", storageBucket: "", messagingSenderId: "", appId: "" }; // Initialize Firebase firebase.initializeApp(firebaseConfig); </script>