How do I remove carrier lock on my iPhone?

You are not talking to Apple. This is a user forum.

Even if you were talking to Apple, they can not remove the carrier lock from a phone.

Only the carrier the phone is locked to can unlock it for use on other carriers.

You will need to contact the carrier the device is locked to and request an unlock. If you don’t know who that is, ask whoever you got the phone from.

Carriers are free to set their own requirements for unlocking within the laws of the country they operate in. As a rule of thumb, if you are not a current or former customer of the carrier the device is locked to, they probably will NOT unlock it.

3rd party unlocking services that advertise on the internet are NOT legitimate. They can not unlock the phone.

Only the carrier can unlock the phone.

Apple cannot unlock the phone.