<!– Google Tag Manager –> {% if site.google-tag_key == “Google Tag Manager key goes here” or site.google-tag_key == nil or site.google-tag_key == '' %}<!– =========================================================================================

YOU NEED TO PUT THE GOOGLE TAG KEY IN THE _config.yml FILE!
============================================================================================ -->{% endif %}

{% if jekyll.environment == “publish” %}{% if site.google-tag_key != “Google Tag Manager key goes here” and site.google-tag_key != nil %} <script>

(function(w, d, s, l, i) {
  w[l] = w[l] || [];
  w[l].push({
    'gtm.start': new Date().getTime(),
    event: 'gtm.js'
  });
  var f = d.getElementsByTagName(s)[0],
    j = d.createElement(s),
    dl = l != 'dataLayer' ? '&l=' + l : '';
  j.async = true;
  j.src =
    'https://www.googletagmanager.com/gtm.js?id=' + i + dl;
  f.parentNode.insertBefore(j, f);
})(window, document, 'script', 'dataLayer', '{{ site.google-tag_key }}');

</script> {% endif %}{%- endif -%} <!– End Google Tag Manager –>