How to Send Custom Data to Email Template

[mfonsatti]

Hi ,
how can i send custom data to an email template ?
the email is sent correctly but the data is not rendered in the template ...

the body of the template is something like
"Lorem ipsum dolor {customName} sit amet"

/* EMAIL PROCESS */
/** @var Email $email */
$email = $this->getEntityManager()->getEntity('Email');
/** @var EmailTemplate $emailTpl */
$emailTpl = $this->getEntityManager()->getEntity('EmailTemplate', $templateId);
//$subjectTpl = $emailTpl->get("subject");
$emailParam = [
    'subject'       => $emailTpl->get("subject"),
    'body'          => $emailTpl->get("body"),
    'isHtml'        => true,
    'from'          => $from,
    'replyTo'       => $replyTo,
    'to'            => $to,
    'customName' => $customValue
];
$email->set($emailParam);
try {
    $this->getContainer()->get("mailSender")->send($email);
} catch (\Exception $e) {
    return [
        'response' => 'error',
        'message'  => 'EmailNotification: [' . $e->getCode() . '] ' . $e->getMessage(),
    ];
}