Function Introduction：
Personal Identification Number is the SIM card's Personal Identification Number.If not modified, the original password set by the carrier is 1234 or 0000.
If the PIN enabled , it is required to enter a 4-digit PIN each power-on. The PIN code can be modified to protect the SIM card from being used by others.
1. Xiaomi phones will not automatically set this function.Xiaomi phones don't support PIN setting, only support the lock screen password,
2. The PIN code of the SIM card is set by the user. If the user forgets it, please consult the operator for PUK (unlock code).
3. If it is necessary to input the PIN code with another SIM card, it is suggested to use the original SIM card of the phone and consult the operator to unlock the phone.