Twitter Auth with Slim3

routes.php

<?php 
use Abraham\TwitterOAuth\TwitterOAuth;

/* This is the basics required for authentication via twitter. The twitter/callback needs to match the returned user id
 * with one in storage and set the account for the current session.
 *
 * 
 */

define('CONSUMER_KEY', '');
define('CONSUMER_SECRET', '');

$app->get('/auth', function (Slim\Http\Request $request, Slim\Http\Response $response, $args) {
    $connection = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET);
    $request_token = $connection->oauth('oauth/request_token', ['oauth_callback' => 'http://localhost:3000/auth/twitter/callback', 'x_auth_access_type' => 'write']);

    $_SESSION['oauth_token'] = $request_token['oauth_token'];
    $_SESSION['oauth_token_secret'] = $request_token['oauth_token_secret'];

    $url = $connection->url('oauth/authorize', array('oauth_token' => $request_token['oauth_token']));
    return $response->withRedirect($url);
});

$app->get('/auth/twitter/callback', function (Slim\Http\Request $request, Slim\Http\Response $response, $args) use($app) {
    $request_token = [];
    $request_token['oauth_token'] = $_SESSION['oauth_token'];
    $request_token['oauth_token_secret'] = $_SESSION['oauth_token_secret'];

    if ($request_token['oauth_token'] !== $request->getParam('oauth_token', null)) {
        die('something went wrong');
    }

    $connection = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET, $request_token['oauth_token'], $request_token['oauth_token_secret']);
    $access_token = $connection->oauth("oauth/access_token", ["oauth_verifier" => $request->getParam('oauth_verifier')]);

    $_SESSION['access_token'] = $access_token;

    return $response->withRedirect('http://localhost:3000/profile');
});

$app->get('/profile', function(Slim\Http\Request $request, Slim\Http\Response $response, $args) {
    $access_token = $_SESSION['access_token'];
    $connection = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET, $access_token['oauth_token'], $access_token['oauth_token_secret']);
    $user = $connection->get("account/verify_credentials");
    var_dump($user);
});

$app->get('/[{name}]', function ($request, $response, $args) {
    // Sample log message
    $this->logger->info("Slim-Skeleton '/' route");

    // Render index view
    return $this->renderer->render($response, 'index.phtml', $args);
});