jsPartLoginPage.js

  //This is for educational purpose and a demo of login system  
  // Your web app's Firebase configuration
  // For Firebase JS SDK v7.20.0 and later, measurementId is optional
  var firebaseConfig = {
    apiKey: "Your API Key Here",
    authDomain: "login-demo-254f7.firebaseapp.com",
    projectId: "login-demo-254f7",
    storageBucket: "login-demo-254f7.appspot.com",
    messagingSenderId: "228883805517",
    appId: "1:228883805517:web:db9063121d6bf3a79ab304",
    measurementId: "G-C8Q2HYKHY1"
  };
  // Initialize Firebase
  firebase.initializeApp(firebaseConfig);

  const auth =  firebase.auth();

  //signup function
  function signUp(){
    var email = document.getElementById("email");
    var password = document.getElementById("password");

    const promise = auth.createUserWithEmailAndPassword(email.value,password.value);
    //
    promise.catch(e=>alert(e.message));
    alert("SignUp Successfully");
  }

  //signIN function
  function  signIn(){
    var email = document.getElementById("email");
    var password  = document.getElementById("password");
    const promise = auth.signInWithEmailAndPassword(email.value,password.value);
    promise.catch(e=>alert(e.message));
    
  }


  //signOut

  function signOut(){
    auth.signOut();
    alert("SignOut Successfully from System");
  }

  //active user to homepage
  firebase.auth().onAuthStateChanged((user)=>{
    if(user){
      var email = user.email;
      alert("Active user "+email);

    }else{
      alert("No Active user Found")
    }
  })