"My Cafe" is free to play, though certain in-game elements can be purchased for real money. To avoid accidental in-app purchases, change your device settings.

For iOS devices:

1. Go to Settings Screen Time, then tap Turn on Screen Time. If you already had Screen Time turned on, skip to step 3.
2. Tap Continue, then choose "This is My [device]" or "This is My Child's [device]."
3. Tap Content & Privacy Restrictions. If asked, enter your passcode, then turn on Content & Privacy. 
4. Tap iTunes & App Store Purchases.
5. Tap In-app Purchases and set to Don't Allow.

If you don't want to restrict in-app purchases completely, you can adjust the password settings for them. Make sure your restrictions are disabled and go to device settings > App Store, iTunes Store > Password Settings.

For Android devices:

1. Open the Play Store app.
2. Tap the your icon in the upper right corner and select Settings.
3. Tap Authentication - Require authentication for purchases.
4. Select one of the authentication options.
- For all purchases through Google Play on this device. Authentication will be required for all Google Play purchases (including in-app purchases).
- Every 30 minutes. The system will request the password for Google Play purchases every 30 minutes. Just note that once you enter the password all purchases made over the following 30 minutes will not need a password.
5. Follow the instructions on the screen.