When you install PushOwl, the PushOwl dashboard will prompt you to subscribe to notifications from your online store, so you can use the ‘Get Test Notification’ feature whenever you need to. If you also subscribe to notifications from your online store separately, you have essentially subscribed twice - once from the PushOwl dashboard (dashboard.pushowl.com) and once from your online store (yourstore.myshopify.com).
Now, sending any campaign to your subscribers will send you two notifications to your device - one each from the PushOwl dashboard and your online store. If that happens, don’t worry about it as your subscribers will be receiving only one notification, containing the URL of your store.
If you want to stop receiving duplicate notifications, you can unsubscribe from either the PushOwl dashboard or your online store.