Checking for Facebook Login on Website from Chrome Extension

I want to check from a Chrome extension if I logged in to my website on Google Chrome using the Facebook SDK from javascript and also get the user access token. Right now I am trying to use the following login request on the website:

However, although I am able to call the “” from the chrome extension, I am unable to get the access token for the login. From the chrome extension, how do I determine if somebody has logged into the web app at and subsequently get their access token?