Open MailChimp Newsletter Popup on Button Click

popup.html

<script type="text/javascript" src="//downloads.mailchimp.com/js/signup-forms/popup/embed.js" data-dojo-config="usePlainJson: true, isDebug: false"></script>
<script type="text/javascript">
  function showNewsletter() {
    // Replace with YOUR list values
    require(["mojo/signup-forms/Loader"], function(L) { L.start({"baseUrl":"YOUR-BASEURL","uuid":"YOUR-UUID","lid":"YOUR-LID"}) });

    // Disable MCPopupClosed cookie for being able to re-open the popup
    document.cookie = "MCPopupClosed=;path=/;expires=Thu, 01 Jan 1970 00:00:00 UTC";

    // Disable MCPopupSubscribed cookie for being able to re-open the popup once suscribed
    document.cookie = "MCPopupSubscribed=;path=/;expires=Thu, 01 Jan 1970 00:00:00 UTC";
  }
</script>

<button type="button" onclick="showNewsletter()">Newsletter</button>