Since the app doesn't allow transactions, you must go to the source using a mobile or desktop browser (Safari, Chrome, or Firefox). Open your browser and go to the Google Play Store . Sign in with the you use for your books.
As a dedicated iOS user, you might have noticed that buying a book inside the Google Play Books app is impossible. This isn't a bug or a missing feature; it is a direct result of the long-standing "Apple Tax"—the 30% commission Apple takes on all in-app purchases of digital goods. To avoid this fee, Google (like Amazon and Spotify) disables direct purchasing within its iPhone app.
Google often runs different sales or offers "Play Points" that can be redeemed for discounts.
By stepping outside the app for just a moment to use a browser, you gain access to a massive library that Apple’s ecosystem doesn't always provide.
Search for the title you want and tap the price button to complete your purchase using your saved Google payment method. Step 2: Sync to Your iPhone
