Function only show on posts

Hi all,

not sure if this is the right place on the forum to ask this but let’s try.
I have a function that shows a linkedin share button on my website. It looks like this:

function wpb_linkedin_share_after($content) { 
$sharecode .= '<script src="//platform.linkedin.com/in.js" type="text/javascript"> lang: en_US</script>
<script type="IN/Share" data-counter="top"></script>'; 
$newcontent = $content . $sharecode; 
return $newcontent; 
} 
add_filter('the_content', 'wpb_linkedin_share_after');

Now i would like this only to show up on “post” types. I read about the part where you have to specify what kind of type of page it is but can’t figure it out.

Thanks for your help!

Sjoerd