Unlock iPhone from carrier

Your iPhone might be locked to your carrier. Unlocking your iPhone means that you can use it with different carriers. To contact your carrier and unlock your iPhone, use these steps. You can find out if your iPhone is locked by going to Settings > General > About. If "No SIM restrictions" appears next to Carrier Lock, your iPhone is unlocked.

If you don’t want to switch carriers and your device is locked because you forgot the passcode, you don’t need to use the steps in this article.

the carrier it's locked to have to do it

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