JSFiddle - React, Tailwind, and code Playground
HTML
<textarea class="inBox"></textarea><button class="btn">send</button>
<div id="mainbox"></div>
JavaScript
$(document).ready(function(){
$('.btn').on('click',function(){
var inpx= $('.inBox').val();
$('#mainbox').append('<p>'+inpx+'</p>');
$('.inBox').val("");
});
});