Magento – Queue order details in rabbitmq when order is placed in Magento2EE

In Magento2 EE,I need to queue to order details instantly when the order is placed. Rabbitmq is our message broker. I have installed rabbitmq and configured to the Magento2EE by following this link https://inviqa.com/blog/magento-2-tutorial-message-queues. . Everything is working fine. I can push the order array to the queue by giving static order ID.

 <?php

namespace Inviqa\MessageQueueExample\Console;

use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;
use Magento\Framework\MessageQueue\PublisherInterface;
use Inviqa\MessageQueueExample\Api\MessageInterface;
use Magento\Sales\Model\Order;

class MessagePublishCommand extends Command
{
    const COMMAND_QUEUE_MESSAGE_PUBLISH = 'queue:message:publish';
    const MESSAGE_ARGUMENT = 'message';
    const TOPIC_ARGUMENT = 'topic';

    /**
     * @var PublisherInterface
     */
    protected $publisher;
    protected $order;


    /**
     * @var string
     */
    protected $message;

    /**
     * {@inheritdoc}
     */
    public function __construct(
        PublisherInterface $publisher,
        MessageInterface $message,
        Order $order,
        $name = null
    ) {
        $this->publisher = $publisher;
        $this->message = $message;
        $this->order = $order;
        parent::__construct($name);
    }

    /**
     * {@inheritdoc}
     */
    protected function execute(InputInterface $input, OutputInterface $output)
    {
        $message = $input->getArgument(self::MESSAGE_ARGUMENT);
        $topic = $input->getArgument(self::TOPIC_ARGUMENT);

        try {

            $_orderId = 000000004; 
            $_order = $this->order->load($_orderId);
            $_items = $_order->getAllVisibleItems();
            foreach ($_items as $_item) {
                $_orderItems[] = [
                    'sku' => $_item->getSku(), 
                    'item_id' => $_item->getId(),
                    'price' => $_item->getPrice(),
                ];

            }
            $message = $_orderItems;

            $this->message->setMessage($message);
            $this->publisher->publish($topic, $this->message);
            /*print_r($message);
            die;*/
           // $output->writeln(sprintf('Published message "%s" to topic "%s"', $message, $topic));
            $output->writeln(sprintf('Published order'));

        } catch (\Exception $e) {
            $output->writeln($e->getMessage());
        }
    }

    /**
     * {@inheritdoc}
     */
    protected function configure()
    {
        $this->setName(self::COMMAND_QUEUE_MESSAGE_PUBLISH);
        $this->setDescription('Publish a message to a topic');
        $this->setDefinition([
            new InputArgument(
                self::MESSAGE_ARGUMENT,
                InputArgument::REQUIRED,
                'Message'
            ),
            new InputArgument(
                self::TOPIC_ARGUMENT,
                InputArgument::REQUIRED,
                'Topic'
            ),
        ]);
        parent::configure();
    }
}

Once the order is placed, for pushing order object i have planned to use sales_order_place_after event. But i'm not sure how to pull the result from observer, to this execute action.