JSFiddle - React, Tailwind, and code Playground

HTML

<textarea style="width:300px;height:100px;" placeholder="Escribe aqui" id="original"></textarea>

<div id="translation" style="border:1px solid;width:300px;height:100px;"></div>

JavaScript

$( document ).ready(function() {
 
    $("#original").keyup(function(){
      $("#translation").html($(this).val().replace(/s/gi,"j"));
    });
    
});