JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.100.2/css/materialize.min.css">
<script src="https://cdnjs.cloudflare.com/ajax/libs/materialize/0.100.2/js/materialize.min.js"></script>
<a href="#call" class="phoneMe btn modal-trigger">Call Now!</a>

  <div id="call" class="modal">
    <div class="modal-content">
      <h4>Call Now!</h4>
      <p>Click to call</p>
    </div>
    <div class="modal-footer">
      <a href="tel:+15014737132" class="modal-action modal-close waves-effect waves-green btn-flat">Call Now</a>
      <a href="#!" class="modal-action modal-close waves-effect waves-red btn-flat">Cancel</a>
    </div>
  </div>

CSS

position: fixed;
  right: 0px;
  bottom: 60px;
  left: 0px;
  margin-left: 50%;
  height: 53px;
  width: 80px;
  background: #228B22;
  color: white;
  text-decoration: none;
  font-size: 20px;
  text-align: center;
  border-radius: 5px;

JavaScript

$('.modal').modal();