I'm sorry about the issue. A PUK or 'Personal Unlocking Key' code is a security feature on mobile devices that protects your SIM card data. A PUK code is required when a SIM Card PIN code has been entered incorrectly a few times. If you have an online account with your phone service provider, then you can log in your account and check. Or you can contact your phone service provider, such as Vodaphone, Orange, etc.
If you need further help, please let me know your phone service provider. Please reply at the box below to continue troubleshooting. Thank you.