JSFiddle - React, Tailwind, and code Playground

HTML

<div id="div1">
    <ul class="dropdown" id="ul1">
       <li>example</li>
    </ul>
<div>

CSS

.hidden {
    visibility: hidden;
}

JavaScript

document.getElementById('div1').onclick=function(){
   var element = document.getElementById("ul1");
    element.classList.add("hidden"); 
};