public function cancel(): self 	{ 		if (!$this->isCancelable()) { 			return $this; 		}  		if (!setting('onesignal_app_id')) { 			return $this; 		}  		CancelPushNotification::dispatch($this->external_id);  		$this->update([ 			'canceled_at' => formatTimestamp(), 		]);  		return $this; 	}