JSFiddle - React, Tailwind, and code Playground

HTML

<div class="dropdown" onload ="init_menu()" >
    <span>Menu</span>
    <ul onclick="init_menu()">
        <li >First Part</li>
        <li>Second Part</li>
        </ul>
    </div>
    <script>
function init_menu()
        {
        t=document.getElementsByClassName("dropdown");                           for(i=0;i<t.length;i++)
        {

             console.log("i am clicked"+t[i],t[i].children[1]);
             t[i].children[1].classList.add("menu-open");
        
        }
   }
    </script>