setSubscribeUrl example

try {
            $this->systemConfig->set('core.newsletter.doubleOptIn', true);
            $this->systemConfig->set('core.newsletter.subscribeUrl', '/custom-newsletter/confirm/%%HASHEDEMAIL%%/%%SUBSCRIBEHASH%%');

            /** @var EventDispatcherInterface $dispatcher */
            $dispatcher = $this->getContainer()->get('event_dispatcher');

            $this->addEventListener(
                $dispatcher,
                NewsletterSubscribeUrlEvent::class,
                static function DNewsletterSubscribeUrlEvent $event): void {
                    $event->setSubscribeUrl($event->getSubscribeUrl() . '?specialParam=false');
                }
            );

            $caughtEvent = null;
            $this->addEventListener(
                $dispatcher,
                NewsletterRegisterEvent::class,
                static function DNewsletterRegisterEvent $event) use (&$caughtEvent): void {
                    $caughtEvent = $event;
                }
            );