<event name="checkout_onepage_controller_success_action">
    <observer name="namespace_module_sales_order_save_after" instance="NamespaceModuleObserverAfterOrder"  />
    </event>

use PsrLogLoggerInterface;
class AfterOrder implements ObserverInterface
{
    protected $_checkoutSession;
    protected $_customerRepositoryInterface;
    protected $_addressInterface;

  public function __construct(
    LoggerInterface $loggerInterface,
    MagentoFrameworkRegistry $registry,
    MagentoSalesModelOrderFactory $orderFactory,
  MagentoQuoteModelQuoteFactory $quoteFactory
    )
  {
      $this->_logger = $loggerInterface;
            $this->orderFactory = $orderFactory;
            $this->registry = $registry;
      $this->quoteFactory = $quoteFactory;
  }

  public function execute(MagentoFrameworkEventObserver $observer)
  {
    $orderId = $observer->getEvent()->getOrderIds();
    $objectManager = MagentoFrameworkAppObjectManager::getInstance();
    $order = $objectManager->create('MagentoSalesModelOrder')->load($orderId[0]);
    $quote = $this->quoteFactory->create()->load($order->getQuoteId());
    echo $order->getQuoteId(); exit;
  }
}

$shippingAddress = $this->checkoutSession->getLastRealOrder()->getShippingAddress();