I don’t know my sim pin

Perhaps you will need to contact your cellular provider and ask.

The Apple support reference article, above this topic thread,

has some helpful bits inside, too.

Use a SIM PIN for your iPhone or iPad - Apple Support

• "If you forgot or don't know your SIM PIN" ~ from reference article:

Never try to guess a SIM 'PIN' or PUK code.*

The wrong guess can permanently lock your SIM card, and then you

would need a new SIM card. IF your device asks for a PIN or code that

you don't know, here's what to do:

1.Contact the carrier that gave you the SIM card. If you aren't sure which carrier to call, remove

your iPhone SIM card or iPad SIM card and check the card for the carrier's name or logo.

2.

3.Ask your carrier to help you unlock your SIM card using the default SIM PIN or PUK code. 

4.IF you can't unlock your SIM card using the SIM PIN or PUK code or if an alert

says, "PUK exhausted," ask for a new SIM card.

*If you enter the wrong SIM PIN too many times, your wireless carrier

might be able to give you a Personal Unlocking Key (PUK).

[Contact your cellular carrier or phone network provider to see what they can do to help.]

[edited 2x]

Hello there,

contact to your carrier to know what is your PIN!