JSFiddle - React, Tailwind, and code Playground

HTML

<select onchange="showme(this);">
  <option value="1">1st option</option>
  <option value="2">2nd option</option>
  <option value="3">3th option</option>
  <option value="4">4th option</option>
</select>
<br><small>For this example, click on popupbox to close it.</small>
<div id="ppb" class="popupbox" onclick="this.style.display='none';"></div>

CSS

.popupbox {
  position:fixed;
  top:50%; left:50%;
  transform:translate(-50%, -50%);
  padding:10px;
  border:solid 2px #808080;
  color:#000;
  background-color:#f1f1f1;
  display:none;
}

JavaScript

function showme(selEle) {
var ppb=document.getElementById('ppb');
ppb.innerHTML='Selected value = '+selEle.value.toString()+'<br>';
ppb.innerHTML+=selEle.options[selEle.selectedIndex].innerHTML;
ppb.style.display='block';
}