Purchased books can only be read or listened to in the BookBeat app. If you want to listen offline, you can download the book within the app. You cannot download the book outside the app for example to an SD card, computer or e-reader.
You can download the BookBeat app to your smartphone or tablet and you need at least iOS 15 or Android 8. You also need access to iOS App Store, Google Play Store or Huawei App Gallery.