However, it also offers "in-app purchases." These purchases are never required to play the game, but can be used to enhance certain aspects of gameplay.
You can easily manage the ability to make in-app purchases, adjust password protection settings, or disable in-app purchases entirely through your mobile device's general settings. How to do this depends on your device.
Here are the instructions you might need:
Apple support: https://support.apple.com/en-us/HT204396
Google support: https://support.google.com/googleplay/answer/1626831?hl=en
Amazon support: https://www.amazon.com/gp/help/customer/display.html?nodeId=201729930
Windows support: https://support.microsoft.com/en-us/help/4026423/microsoft-store-change-purchase-sign-in-settings