我使用Firebase为我的React项目创建了一个Firebase类，但该文件返回以下错误:

TypeError:firebase_app__webpack_imported_module_0__.app.InitializeApp不是函数

我该怎么办？

下面是代码:

import 'firebase/app';
import { app } from 'firebase/app';
import 'firebase/auth';


var firebaseConfig = {
    // config stuff
  };

  class Firebase{
      
      constructor(){
          app.initializeApp(firebaseConfig);
          this.auth = app.auth()
      }

       // *** Auth API ***
 
    doCreateUserWithEmailAndPassword = (email, password) =>
    this.auth.createUserWithEmailAndPassword(email, password);

    doSignInWithEmailAndPassword = (email, password) =>
    this.auth.signInWithEmailAndPassword(email, password);

  }

  export default Firebase;