Get Facebook Auth token from Azure Easy API

Easy API are very poorly documented, I'm trying to get the Facebook Auth token from a user authenticated against it through Azure, I've created an API with the following GET:

module.exports = {
    "get": function (req, res, next) {
        res.json(req.user.getIdentity("facebook"));
    }
};

However azure responds with "cannot read property 'getIdentity' from undefined". If user is undefined in res, where can I get it from?