Start: End:
<!-- advertising B3wZ-eTyieAWazsFeCVOO9Zjgy_XMv-JV3RDEs3I5PPkRnhzXJU7NHjfr49u7QOCywl2qhqePyfocEm5CEpiEw==-->
							<script data-cfasync="false"  id="clevernt" type="text/javascript">
							 (function (document, window) {
                var c = document.createElement("script");
                c.type = "text/javascript";
                c.async = !0;
                c.src = "//clevernt.com/scripts/9e794f6fdc4d6953068697e9941fe288.min.js?20180628=" + Math.floor((new Date).getTime());
                var a = !1;
                try {
                    a = parent.document.getElementsByTagName("script")[0] || document.getElementsByTagName("script")[0];
                } catch (e) {
                    a = !1;
                }
                a || ( a = document.getElementsByTagName("head")[0] || document.getElementsByTagName("body")[0]);
                a.parentNode.insertBefore(c, a);
            })(document, window);
                                </script>
                                <!-- end advertising -->

Copy the code.
Paste it on the source code of your website, near the bottom, just before </body>

ex: same way you insert the google analytics script/code

In case you're using banners, you also need to add the Mobile Tag: <ins class='hstpnetworkads' style='display: inline-block; width: 300px; height: 600px'></ins>