How to configure WebSocket with Apache + Ratchet + SSL?

I have a problem with a websocket server. It’s also my first time with this tech.
I’m using :

• Apache
• Ratchet (PHP)
• SSL (HTTPS on 443 as usual)

I was using this source to make my configuration (it’s in French).

But I can’t connect to my websocket from client with js. I’m still getting this error :

WebSocket connection to ‘wss://server_name.fr/ws/game’ failed

Here is my config file for my site :

<VirtualHost server_name.fr:443>
        #ServerName www.example.com

        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html/server_name/public/
        <Directory /var/www/html/server_name/>
                AllowOverride All       
        </Directory>

        <Location "/ws/game">
                ProxyPass wss://localhost:1176
                ProxyPassReverse wss://localhost:1176
        </Location>

The JS :

var conn = new WebSocket('wss://server_name.fr/ws/game');
conn.onopen = function(e) {
    console.log("Connection established!");
};

conn.onmessage = function(e) {
    console.log(e.data);
};

The PHP Server that I’m runnning on port 1176 (Almost exactly the exemple):

<?php require __DIR__ . '/vendor/autoload.php';

use RatchetServerIoServer;
use RatchetHttpHttpServer;
use RatchetWebSocketWsServer;
use RatchetMessageComponentInterface;
use RatchetConnectionInterface;

define('APP_PORT', 1176);

class ServerGame implements MessageComponentInterface
{
    protected $lobby;
    protected $rooms;
    protected $client_in_room;

    public function __construct()
    {
        $this->lobby = array();
    }

    public function onOpen(ConnectionInterface $conn)
    {

    }

    public function onMessage(ConnectionInterface $conn, $msg)
    {

    }

    public function onClose(ConnectionInterface $conn)
    {

    }

    public function onError(ConnectionInterface $conn, Exception $e)
    {

    }
}

$server = IoServer::factory(
    new HttpServer(
        new WsServer(
            new ServerGame()
        )
    ),
    APP_PORT
);
echo "Server created on port " . APP_PORT . "nn";
$server->run();

Thanks for your help !