Tracking info empty in shipment email in Magento 2

Question

I have created a shipment by adding Tacking info. I am getting the shipment email with empty Tacking info.

Next time if i click on "send Tracking Information. Then I will get the tracking info in shipment email.

My Magento version is 2.3.5

here is the screenshot of shipment email

I need to get this info during shipment creation.

Hopefully its because i used this event to send shipment email automatically whenever the shipment is created.

Vendor/Module/etc/events.xml

<event name="sales_order_shipment_save_after">
    <observer name="sales_order_shipment_after"
              instance="Vendor\Module\Observer\SalesOrderShipmentAfter" />
</event>

Vendor/Module/Observer/SalesOrderShipmentAfter.php

use Magento\Framework\Event\ObserverInterface;
class SalesOrderShipmentAfter implements ObserverInterface
{
    protected $shipmentNotifier;
    protected $_logger;
    public function __construct(
    \Psr\Log\LoggerInterface $logger,       
    \Magento\Shipping\Model\ShipmentNotifier $shipmentNotifier
) {
    $this->_logger = $logger;
    $this->shipmentNotifier = $shipmentNotifier;
}
public function execute(\Magento\Framework\Event\Observer $observer)
{
    try{
        $this->_logger->info('inside shipment observer');
        $shipment = $observer->getEvent()->getShipment();
        $this->shipmentNotifier->notify($shipment);
        //$shipment->save();
    }catch (\Exception $e) {
        $this->_logger->info('--shipment observer--'.$e->getMessage());
    } 
  }
}

Can anyone please help me on this. Thanks

Answer 1

Step 1: First create event.xml

Path- app\code\Vendor\Extension\etc\events.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
    <event name="sales_order_shipment_save_after">
          <observer name="track_shipment" instance="Vendor\Extension\Observer\Shipment" />
     </event>
</config>

Step 2: Then enter the following code in Observer.

Path – app\code\Vendor\Extension\Observer\Shipment.php

<?php
namespace Vendor\Extension\Observer;
use Magento\Framework\Event\ObserverInterface;
class Shipment implements ObserverInterface
{
    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        try {
            $shipment = $observer->getEvent()->getShipment();
            $tracksCollection = $shipment->getTracksCollection();

            foreach ($tracksCollection->getItems() as $track) {
                $track_number = $track->getTrackNumber();
                $carrier_name = $track->getTitle();
            }
        } catch (\Exception $e) {
        }
    }
}


?>