The respective platforms, Play Store for Android and App Store for iOS handle all purchases and payments. Your payment method is stored in your app store account settings. Please follow the next steps depending on the store you use.

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, the sharing organizer can only edit your payment information.
4. Add, edit, or remove the information. Tap None to remove a payment method.
5. Tap Done.

IMPORTANT: As soon as you change your payment method/information, you may see a temporary authorization hold on your means of payment. Please note that iTunes does that to ensure your new payment account is valid and 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.

That’s it, you’re all set!