JSFiddle - React, Tailwind, and code Playground

HTML

<div class="form-group">
        <input id="checkbox" type=checkbox>
      </div>

      <div id="delivery" style="display:none;">
        <div class="form-group">
          HIDDEN
        </div>
      </div>

JavaScript

var checkbox = document.getElementById('checkbox');
var delivery_div = document.getElementById('delivery');
checkbox.onclick = function() {
    console.log(this);
   if(this.checked) {
     delivery_div.style['display'] = 'block';
   } else {
     delivery_div.style['display'] = 'none';
   }
};