Unlock free sim

If uo have an carrier locked iPhone, see this Apple article: How to unlock your iPhone for use with a different carrier

How to unlock your iPhone for use with a different carrier - Apple Support

Apple can't unlock your iPhone for use with a different carrier. Only your carrier can unlock your iPhone.

You need to contact your Carrier.

Contact your current Carrier and ask them to unlock the SIM card. Only the carrier can unlock the SIM card.

They may or may not agree to do this though.