How to finish exchanging temporary token for Shopify-node-api on Express Node.js?

I've got the install to run using this guide...

https://www.npmjs.com/package/shopify-node-api

But my http://localhost:3000/finish_auth page is refusing to connect. This is what my finish_auth.js file looks like...

var express = require('express');
var router = express.Router();

/* GET home page. */
router.get('/', function(req, res, next) {
  var Shopify = new shopifyAPI(config), 
    query_params = req.query;

  Shopify.exchange_temporary_token(query_params, function(err, data){

  });
});

module.exports = router;

My app.js is the following...

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var expressHandlebars = require('express-handlebars');

var index = require('./routes/index');
var users = require('./routes/users');
var finish_auth = require('./routes/finish_auth')

var app = express();

app.set('views', path.join(__dirname, 'views'));
app.engine('handlebars', expressHandlebars({defaultLayout: 'main'}));
app.set('view engine', 'handlebars');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use('/', index);
app.use('/users', users);
app.use('/finish_auth', finish_auth);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

Any help? I'd like to test by requesting something?

via CDBoi