It’s not possible to purchase audiobooks through the app at this time. Please visit the Libro.fm website to buy your audiobooks. We recommend adding a website bookmark link to Libro.fm on the homescreen of your phone to easily access the website (how to set up a bookmark on iOS). Purchased audiobooks will automatically appear in your Library. However, you might need to refresh your app by swiping down in the library or by opening and closing the app.