Google Ad sense not working

[Title de-capitalized; please do not shout at us]

The code of mine is

<script async
src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<!-- WORDPRESS -->
<ins class="adsbygoogle"
     style="display:block"
     data-ad-client="ca-pub-3052467509614255"
     data-ad-slot="9377012728"
     data-ad-format="auto"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});

when I pasted this to wordpress text in widgets it is displaying no ads but just this as below

//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js
(adsbygoogle = window.adsbygoogle || []).push({});