ExampleTransport.php

<?php

/*
 * @copyright   2020 Mautic Contributors. All rights reserved
 * @author      Mautic
 *
 * @link        http://mautic.org
 *
 * @license     GNU/GPLv3 http://www.gnu.org/licenses/gpl-3.0.html
 */

namespace MauticPlugin\ExampleBundle\Integration\ExampleIntegration;

class ExampleTransport implements TransportInterface, TransportSettingsInterface
{
    
    ....
    
    /**
     *  Define which settings your transport support.
     *
     * @return array
     */
    public function enabledSettings()
    {
        [
            TransportSettingsInterface::STAT_DELIVERED,
            TransportSettingsInterface::STAT_READ,
            TransportSettingsInterface::STAT_FAILED,
        ];
    }
}