How to create a shipment programmatically in Magento 2

CreateShipment.php

<?php

class CreateShipment extends \Magento\Backend\App\Action
{
    /**
     * The OrderRepository is used to load, save and delete orders.
     *
     * @var \Magento\Sales\Model\OrderRepository
     */
    protected $orderRepository;

    /**
     * The ShipmentFactory is used to create a new Shipment.
     *
     * @var Order\ShipmentFactory
     */
    protected $shipmentFactory;

    /**
     * The ShipmentRepository is used to load, save and delete shipments.
     *
     * @var Order\ShipmentRepository
     */
    protected $shipmentRepository;

    /**
     * The ShipmentNotifier class is used to send a notification email to the customer.
     *
     * @var ShipmentNotifier
     */
    protected $shipmentNotifier;

    /**
     * All specified parameters in the constructor will be injected via dependency injection.
     *
     * @param \Magento\Backend\App\Action\Context $context
     */
    public function __construct(
        \Magento\Backend\App\Action\Context $context,
        \Magento\Sales\Model\OrderRepository $orderRepository,
        \Magento\Sales\Model\Order\ShipmentRepository $shipmentRepository,
        \Magento\Sales\Model\Order\ShipmentFactory $shipmentFactory,
        \Magento\Shipping\Model\ShipmentNotifier $shipmentNotifier,
    ) {
        parent::__construct($context);

        $this->orderRepository = $orderRepository;
        $this->shipmentFactory = $shipmentFactory;
        $this->shipmentRepository = $shipmentRepository;
        $this->shipmentNotifier = $shipmentNotifier;
    }

    /**
     * Since our class extends the Magento Action class it *must* have an execute() function.
     * This function is automatically called as soon as the request is sent.
     * @return void
     */
    public function execute()
    {
        // we are assuming that the order ID passed to this action via the request parameter.
        $orderId = $this->getRequest()->getParam('order_id', 0);

        if ($orderId <= 0) {
            echo 'Order not found.';
            return;
        }

        try {
            // load order from database
            $order = $this->orderRepository->get($orderId);

            if ($order == null) {
                echo "Order not loaded from database."
                return;
            }

            $this->createShipment($order);

        } catch (\Exception $exception) {
            echo 'Error: ' . $exception->getMessage();
        }
    }

    /**
     * Creates a new shipment for the specified order.
     *
     * @param \Magento\Sales\Model\Order $order
     */
    protected function createShipment($order)
    {
        // check if it's possible to ship the items
        if ($order->canShip()) {
            // create the shipment
            $shipment = $this->shipmentFactory->create($order);

            // save the newly created shipment
            $this->shipmentRepository->save($shipment);

            // send shipping confirmation e-mail to customer
            $this->shipmentNotifier->notify($shipment);
        }
    }
}

I am receiving this error message: We cannot create an empty shipment

Can you show me a sample of an order that you’re trying to ship?

hi @fahu.
What do you mean by sample of the order? I just have a normal order collection and I tried to use your code in the loop. I have nothing special with my orders. They were created manual from the backend . Thanks :)