Use XCLASSing to extend base contact model and add additional fields.
<?php
declare(strict_types=1);
use Remind\Contacts\Domain\Model\Contact as DefaultContact;
use Remind\Extension\Domain\Model\Contact;
defined('TYPO3') || die('Access denied.');
(function (): void {
$GLOBALS['TYPO3_CONF_VARS']['SYS']['Objects'][DefaultContact::class] = ['className' => Contact::class];
})();To add fields to the VCard simply use XCLASSing like described before and override the getVCard method.
<?php
declare(strict_types=1);
namespace Remind\Extension\Domain\Model;
use Remind\Contacts\Domain\Model\Contact as BaseContact;
use Sabre\VObject\Component\VCard;
class Contact extends BaseContact
{
public function getVCard(): VCard
{
$result = parent::getVCard();
$result->add(
'TITLE',
['Remind Developer'],
);
return $result;
}
}