code: public function created(JWTCreatedEvent $event)
      {
          $payload = $event->getData();
          $user = $event->getUser();
          $payload[$this->attribute] = $user->getTenant();
          $event->setData($payload);
      }
docs: Add the user tenant to the token
  
  @param \Lexik\Bundle\JWTAuthenticationBundle\Event\JWTCreatedEvent $event