Установил сертификат:
server{
listen 8443 ssl;
ssl_certificate /etc/ssl/sert.crt;
ssl_certificate_key /etc/ssl/sert.key;
server_name site.ru;
}
Теперь такая ошибка: WebSocket connection to 'wss://site.ru:8443/components/socket.php' failed: Error during WebSocket handshake: Unexpected response code: 404