Set Parental Controls for In-App Purchases
You can set Parental Controls to add security for in-app purchases on your device.
To set Parental Controls for in-app purchases:
Launch the Amazon Appstore for Android app on your device.
Open the menu, tap Settings, and then tap Parental Controls.
Select Enable Parental Controls, and then enter your Amazon account password. Once you do this, entry of your Amazon account password will be required to complete any in-app purchases on your device.
You also have the option to require a PIN for in-app purchases instead of your account password. To do this, select Use PIN after enabling parental controls from the Settings menu.
You may see a prompt to enter your parental controls password or purchase PIN more than once in a session, based on Amazon's standard password protection features.
Parental Controls only apply to in-app purchasing and aren't supported for all Amazon Appstore orders. Fire Tablets have device-specific parental controls you can use to manage Appstore purchasing options. For more information, go to Kindle SupportKindle Support
and select your device.
For more information about turning off in-app purchasing, go to Turn Off In-App Purchasing.