JSFiddle - React, Tailwind, and code Playground

HTML

<form action="#" method="post">
    <fieldset>
        <label for="first">First:</label>
        <input type="text" id="first" name="first" />
        <input type="hidden" name="hidden" value="something" />
    </fieldset>
</form>

JavaScript

$(document).ready(
    function(){
     $('<input type="text" />')
      .appendTo('form')
         .val($('input:hidden').val())
         .attr('name',$('input:hidden').attr('name'))
         .remove('input:hidden');
    }
    );