In Match & Catch 3D, there are in-app purchases that can be made to purchase in-game items.
But you can set your device settings to avoid any accidental purchases.

1. Go to device settings
2. Select [Screen Time]
3. Select [Content & Privacy Restrictions]
4. Go to iTunes & App Store Purchases
5. Go to [In-app purchases] and select [Don’t Allow]

A detailed guide on how to disable in-app purchases is available here:
▶Prevent in-app purchases from the App Store: https://support.apple.com/en-us/HT204396

If you do not want to disable in-app purchases but you want to enter a password every time you make an in-app purchase, please check the following guide.
▶Require a password for App Store and iTunes purchases: https://support.apple.com/en-us/HT204030