If you would like to get a basic subscriber export on your own (subscribers by city, state, country, os, device, etc.)
Then follow the steps found in this document here
Generally speaking, website push notification subscribers have two aspects to them, their "device token" and a corresponding "key". You need both parts not only to send notifications to subscribers, but to export them as well.
As a result, you will only be able to export your website push notification subscribers if you have added your own custom GCM/FCM Keys. You can read more on how to do that here: Adding Custom FCM ID & Key
Google Cloud Messaging (commonly referred to as GCM) is a mobile notification service developed by Google that enables third-party application developers to send push notifications. In 2016 GCM has been superseded by Google's Firebase Cloud Messaging (FCM).
If you've already added your GCM/FCM keys, then you can email firstname.lastname@example.org and we will provide you a full export of your subscribers. Please note that you will only be able to export those subscribers you gained since adding your custom GCM/FCM keys.
If you haven't added your GCM/FCM keys but want to export your subscribers, you're still partially in luck.
Unlike many other push notification service providers, Aimtell makes it so your website visitors subscribe directly to your website (ie yoursite.com instead of yoursite.aimtell.com). This means that subscribers have already given your website permission and can automatically be opted back in when revisiting your site without showing them the push opt-in prompt.