All purchases and payments are handled by the store you used to download the game from. Your payment method is also stored in your app store account settings, so depending on the store you use follow the next steps:

For the App Store:
1. Open device settings -> iTunes & App Store.
2. Tap your Apple ID email and select View Apple ID. You may be asked to log into your account.
3. Select Payment Information. If your device is associated with Family sharing, your payment information can only be edited by the sharing organizer.
4. Add, edit or remove the information. Tap None to remove a payment method.
5. Tap Done.

IMPORTANT NOTE: Once you’ve changed your payment method, you may see a temporary authorization hold for a small amount on your payment card (iTunes does that to make sure your new payment account is active).

For Google Play:
1. Open Play Store.
2. Tap menu -> Account.
3. Choose Payment methods -> More payment settings.
4. Enter your Google Payments account if asked to do so.
5. Tap Menu in the browser -> Payment methods.
6. Tap Add to add a new method or Edit under the selected payment method.
7. Apply the changes and tap Save.

For the Amazon Appstore:
1. Open Manage Your Content and Devices.
2. Select Settings -> Edit Payment Method.
3. Enter your changes and tap Continue.

And that's it! You're all set. Happy gaming! 🎮