ログイン画面をブラウザで確認したい

ドットインストールのレッスンに沿って進めてきましたが、ログイン画面をブラウザに表示することができません。
（レッスン名：PHPでログイン機能を実装しよう　» #08 ログイン画面を作っていこう）

ご助言頂けますと幸いです。

＜確認手順＞

ターミナルに下記コマンドを入力し、ビルトインWEBサーバーを立ち上げる。

php -S 192.168.33.10:8000 -t public_html/

Listening on http://192.168.33.10:8000と表示されるので、Chromeで検索バーにhttp://192.168.33.10:8000を入力。

＜ターミナルで返ってきたエラーメッセージ＞

[Thu Mar 20 16:44:54 2020] PHP Warning:  require_once(/home/vagrant/sns_php/config/../lib/functions.php): failed to open stream: No such file or directory in /home/vagrant/sns_php/config/config.php on line 11
[Thu Mar 20 16:44:54 2020] PHP Fatal error:  require_once(): Failed opening required '/home/vagrant/sns_php/config/../lib/functions.php' (include_path='.:/usr/share/pear:/usr/share/php') in /home/vagrant/sns_php/config/config.php on line 11
[Thu Mar 20 16:44:54 2020] 192.168.33.1:56996 [200]: / - require_once(): Failed opening required '/home/vagrant/sns_php/config/../lib/functions.php' (include_path='.:/usr/share/pear:/usr/share/php') in /home/vagrant/sns_php/config/config.php on line 11
[

＜ブラウザ上の表示＞

Warning: require_once(/home/vagrant/sns_php/config/../lib/functions.php): failed to open stream: No such file or directory in /home/vagrant/sns_php/config/config.php on line 11

Fatal error: require_once(): Failed opening required '/home/vagrant/sns_php/config/../lib/functions.php' (include_path='.:/usr/share/pear:/usr/share/php') in /home/vagrant/sns_php/config/config.php on line 11

＜各ファイルの内容＞

php
1//vagrant/sns_php/config/autoload.php
2
3<?php
4
5/*
6MyApp
7index.php controller
8MyApp\Controller\Index
9-> lib/Controller/Index.php
10*/
11
12spl_autoload_register(function($class) {
13  $prefix = 'MyApp\';
14  if (strpos($class, $prefix) === 0) {
15    $className = substr($class, strlen($prefix));
16    $classFilePath = __DIR__ . '/../lib/' . str_replace('\', '/', $className) . '.php';
17    if (file_exists($classFilePath)) {
18      require $classFilePath;
19    }
20  }
21});

php
1//vagrant/sns_php/config/config.php
2
3<?php
4
5ini_set('display_errors', 1);
6
7define('DSN', 'mysql:dbhost=localhost;dbname=dotinstall_sns_php');
8define('DB_USERNAME', 'dbuser');
9define('DB_PASSWORD', 'mu4uJsif');
10
11define('SITE_URL', 'http://' . $_SERVER['HTTP_HOST']);
12
13require_once(__DIR__ . '/../lib/functions.php');
14require_once(__DIR__ . '/autoload.php');
15
16session_start();

sql
1//vagrant/sns_php/config/init.sql
2
3create database dotinstall_sns_php;
4
5grant all on dotinstall_sns_php.* to dbuser@localhost identified by 'mu4uJsif';
6
7use dotinstall_sns_php
8
9create table users (
10  id int not null auto_increment primary key,
11  email varchar(255) unique,
12  password varchar(255),
13  created datetime,
14  modified datetime
15);
16
17desc users;

php
1//vagrant/sns_php/lib/Controller.php
2
3<?php
4
5namespace MyApp;
6
7class Controller {
8
9  protected function isLoggedIn() {
10    // $_SESSION['me']
11    return isset($_SESSION['me']) && !empty($_SESSION['me']);
12  }
13
14}

php
1//vagrant/sns_php/lib/function.php
2
3<?php
4
5function h($s) {
6  return htmlspecialchars($s, ENT_QUOTES, 'UTF-8');
7}

php
1//vagrant/sns_php/lib/Controller/Index.php
2
3<?php
4
5namespace MyApp\Controller;
6
7class Index extends \MyApp\Controller {
8
9  public function run() {
10    if (!$this->isLoggedIn()) {
11      // login
12      header('Location: ' . SITE_URL . '/login.php');
13      exit;
14    }
15
16    // get users info
17  }
18
19}

php
1//vagrant/sns_php/public_html/index.php
2
3<?php
4
5// ユーザーの一覧
6
7require_once(__DIR__ . '/../config/config.php');
8
9$app = new MyApp\Controller\Index();
10
11$app->run();

php
1//vagrant/sns_php/public_html/login.php
2
3<?php
4
5// ログイン
6
7require_once(__DIR__ . '/../config/config.php');
8
9// $app = new MyApp\Controller\Login();
10//
11// $app->run();
12
13echo "login screen";
14exit;