Simple login
<!DOCTYPE html>
<html>
<head>
<title>Login</title>
</head>
<body>
<script>
let passwort = prompt("What is the Password");
if (passwort == "test"){
window.open("https://www.w3schools.com"); //Not Secure
}
</script>
</body>
</html>
<!-- Note, this is not a Secure login. Any Body can see the Password in the Source Code -->