我需要一个示例html javascript来做CRUD操作使用Firebase

<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-database.js"></script>

// 替换为你的Firebase项目配置
var firebaseConfig = {
  apiKey: "YOUR_API_KEY",
  authDomain: "YOUR_AUTH_DOMAIN",
  databaseURL: "YOUR_DATABASE_URL",
  projectId: "YOUR_PROJECT_ID",
  storageBucket: "YOUR_STORAGE_BUCKET",
  messagingSenderId: "YOUR_MESSAGING_SENDER_ID",
  appId: "YOUR_APP_ID"
};

// 初始化Firebase
firebase.initializeApp(firebaseConfig);

// 获取数据库引用
var database = firebase.database();

// 创建数据
function createData(data) {
  var newDataRef = database.ref().push();
  newDataRef.set(data);
}

// 读取数据
function readData() {
  database.ref().once('value').then(function(snapshot) {
    snapshot.forEach(function(childSnapshot) {
      var childData = childSnapshot.val();
      console.log(childData);
    });
  });
}

// 更新数据
function updateData(key, newData) {
  var dataRef = database.ref(key);
  dataRef.update(newData);
}

// 删除数据
function deleteData(key) {
  var dataRef = database.ref(key);
  dataRef.remove();
}