iOS

To set in-app purchase restrictions:

1. Open the Settings app, tap "Screen Time," enable Screen Time if you haven't already done so, then tap "Content & Privacy Restrictions."
2. Tap the switch next to Content & Privacy Restrictions to enable the options below it.
3. Tap "iTunes & App Store Purchases."

On Apple devices, you have two options to restrict in-app purchases: Always require a password for in-app purchases or disallow in-app purchases entirely.

To disable in-app purchases entirely, tap "In-app Purchases" and select "Don't Allow." To require a password for in-app purchases, select "Always Require" under REQUIRE PASSWORD.

Visit Apple Support for more information on enabling purchasing restrictions. Parents can also use the "Ask to Buy" feature to limit their children's access to purchasing.

Android

On Android, you can restrict in-app purchases by requiring a password for each in-app purchase:

1. Open the Google Play Store app.
2. Tap Menu > Settings > Require Authentication for Purchases.
3. Select the "For all purchases through Google Play on this device" option.

For fingerprint authentication:
1. Open the Google Play app.
2. Tap the profile icon at the top right.
3. Tap Settings, then Authentication.
4. Turn on Biometric authentication.
5. Enter your password and tap OK.
Tip: To set up fingerprint authentication, you will need your Google password.