JSFiddle - React, Tailwind, and code Playground

HTML

<?php @session_start();
  $_SESSION['flag']=0;
  ?>


<span id="bag">Add To Bag</span>	
	<div id="login">This is your bag</div>
	
	<div id="notlogin">Please login first
		<form action="config-haslogin.php" method="post">
			Name:  <input type="text" id="name" name="name" />
			E:mail <input type="text" id="email" name="email" />
		</form>
	</div>

CSS

div {display:none;}

JavaScript

$(document).ready(function(){
    check = "<?= $_SESSION['flag'] ?>";
    $("#bag").click(function(){
        if(check==0){
            $("#login").show();
            $("#notlogin").hide();
        } else {
            $("#login").hide();
            $("#notlogin").show();
        }
    });
});