JSFiddle - React, Tailwind, and code Playground

HTML

<table>
 <tr>
   <td>
     <form id="form1" onsubmit="submitFrame()">
       <input class="botao" type="button" onclick="submitFrame()" value="Update" style="width: 120px;">
     </form>
   </td>
 </tr>
</table>

<iframe src="" name= "UpdIframe" id= "UpdIframe" style="display:none;border:2px solid blue" height="200" width="400"> hello </iframe>

JavaScript

window.submitFrame = function(){
	document.getElementById('UpdIframe').style.display = "block";
}