JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.14.0/jquery.validate.min.js"></script>
<form id="myform" action="post.php">
    <input type="text" name="first_name" />
    <br/>
    <input type="text" name="last_name" />
    <br/>
    <input type="text" name="phone" />
    <br/>
    <input type="submit" />
</form>
<a href="http://jqueryvalidation.org" target="_blank">Official jQuery Validation Documentation</a>

CSS

a {
    display: block;
    position: absolute;
    bottom: 0;
}

JavaScript

$(document).ready(function() { // <-- ensure form's HTML is ready

    $("#myform").validate({ // <-- initialize plugin on the form.
        // your rules and other options,
        rules: {
            first_name: { // <-- this is the name attribute, NOT id
                required: true
            },
            last_name: {
                required: true
            },
            phone: {
                required: true,
                digits: true
            }
        }
    });

});