JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<script src="https://ajax.aspnetcdn.com/ajax/jquery.validate/1.15.0/jquery.validate.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.css">
<script src="https://cdn.datatables.net/1.10.12/js/jquery.dataTables.min.js"></script>
<link rel="stylesheet" href="https://cdn.datatables.net/1.10.12/css/jquery.dataTables.min.css">
<form id="frm">
  <select name="slct">
    <option value="">Select</option>
  </select>
  <input type="submit" value="submit">
</form>

CSS

.error{
  color: red;
}

JavaScript

$("#frm").validate({
  rules: 
  {
  	slct: {
    	required: true
    }
  }
});