JSFiddle - React, Tailwind, and code Playground

HTML

<button  id="btn">click me!</button>

<hr/>


<div id="a" style="display:none">
     A
</div>


<div id="b" >
      B
</div>

JavaScript

function clicked_about(){
    
    
    document.getElementById("a").style.display = 'block';
    document.getElementById("b").style.display = 'none';
}

document.getElementById("btn").onclick=function(){clicked_about();};