How do we implement Google AdSense on our website?

Every time we try to input an ad code onto the header of our website, it is shortened and comes up as text in the header. This is the code that is inputted:
<script async src=”//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js”></script>
<!– Top Bar Responsive –>
<ins class=”adsbygoogle”
style=”display:block”
data-ad-client=”ca-pub-3632691298585172″
data-ad-slot=”1379202045″
data-ad-format=”auto”></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>
And when it is saved, this is the code that comes out:
<!– Top Bar Responsive –>
<ins class=”adsbygoogle”></ins>
(adsbygoogle = window.adsbygoogle || []).push({});
How do we format the code so the ad comes up on the site?