I copied the code from this link by giving company name and clicking the Get Code button. It generated the code given below
Well it appears that you are just invoking the JavaScript. You must place the JavaScript into an HTML Document and then have an element that corresponds with that script.
Remember you also have to have a full structured HTML Document before you can just place Script tags into it, you need html, body, head, tags, etc.
Try creating an HTML Document and placing this within the .html file.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
</head>
<body>
<script src="//platform.linkedin.com/in.js" type="text/javascript"></script>
<script type="IN/FollowCompany" data-id="361557" data-counter="right"></script>
</body>
</html>
Tips to remember:
Hope this helps!
EDIT: Just upload it to a server, once you do that, it will work. I cannot explain why though.
It is not working locally because it is using protocol relative URL. If you change src="//platform.linkedin.com/in.js"
to src="https://platform.linkedin.com/in.js"
it will work.