JavaScript Firebase登录集成:未捕获ReferenceError:未定义signIn

<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-auth.js"></script>

const firebaseConfig = {
  // 在这里填写你的Firebase配置信息
};

firebase.initializeApp(firebaseConfig);

const email = "user@example.com";
const password = "password";

firebase.auth().signInWithEmailAndPassword(email, password)
  .then((userCredential) => {
    // 登录成功后的处理逻辑
    const user = userCredential.user;
    console.log("登录成功", user);
  })
  .catch((error) => {
    // 登录失败后的处理逻辑
    console.log("登录失败", error);
  });