Hi, what are you trying to do? Just use fb login, or...?
Theres a lot of stuff involved for fb to work, not just within C2 but also on fb developer site.
I just wanted to share a link from googleplay to facebook. I done it before when I just made games in pure HTML + Javascript , I didn't need to do anything in Facebooks end just code it in my game. But you don't have that type of editor with Construct 2 so I have to use plugin.
Straight Code is like this
<body>
<!-- Load Facebook SDK for JavaScript -->
<div id="fb-root"></div>
<script>(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;
js = d.createElement(s); js.id = id;
js.src = "//connect.facebook.net/en_US/sdk.js#xfbml=1";
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));</script>
<!-- Your share button code -->
<div class="fb-share-button"
data-href="www.scirra.com"
data-layout="button_count">
</div>
</body>