What kind of phone do you have, and what is the message you're getting?
On my Samsung S7, these are the messages/prompts I was shown and what they meant:
"SIM network PIN blocked. Enter SIM network PUK."
- This is asking for Samsung's "master code" - I got this after entering the wrong code for the message below too many times. Samsung and/or your previous carrier can give you this.
"SIM network unlock PIN"
- This is asking for your previous carrier's unlock code - just contact them with your IMEI and they'll give it to you easy peasy. If you enter this incorrectly too many times, you'll get the error message above.
