JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://code.jquery.com/mobile/1.0b2/jquery.mobile-1.0b2.min.css">
<div data-role="page" id="home"> 
    <div data-role="content">
 
            <label for "rabat">Rabat:</label><input name="rabat" type="number"><br>
            <label for "cenastart">Cena wyjsciowa:</label><input name="cenastart" type="number">  <br> 
              <label for "cena">Cena po rabacie:</label><input name="cena" type="number">  
          
        
         <p><button id="btn1">Przelicz rabat</button></p> 
    </div>
</div>

JavaScript

$("#btn1").click(function() {  
 $('#cena').append('update input value cena'); 

$('#home').trigger('create');});