如何将firebase firestore连接到实时数据库？

<script src="https://www.gstatic.com/firebasejs/9.0.2/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/9.0.2/firebase-firestore.js"></script>

const firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "YOUR_AUTH_DOMAIN",
  projectId: "YOUR_PROJECT_ID",
  storageBucket: "YOUR_STORAGE_BUCKET",
  messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
  appId: "YOUR_APP_ID"
};

firebase.initializeApp(firebaseConfig);

const db = firebase.firestore();

db.collection("users").get().then((querySnapshot) => {
  querySnapshot.forEach((doc) => {
    console.log(doc.id, " => ", doc.data());
  });
});

db.collection("users").add({
  name: "John Doe",
  age: 30,
  email: "johndoe@example.com"
})
.then((docRef) => {
  console.log("Document written with ID: ", docRef.id);
})
.catch((error) => {
  console.error("Error adding document: ", error);
});

db.collection("users").doc("user1").onSnapshot((doc) => {
  console.log("Current data: ", doc.data());
});