Hello , my device is locked carrier, can help me please

Neither we, just users like you, nor Apple can help you about that problem. Only the carrier whom that iPhone is locked to can unlock it, if you're eligible.

See this support article about the same matter:--> How to unlock your iPhone for use with a different carrier - Apple Support

Regards

Giulio

Hello mehroj240,

You will need to contact AT&T to remove the Activation Lock on your iPhone. Contact their support team and ask for it to be removed or how to remove it.

Please keep in mind if you’ve not finished paying off the phone through AT&T, they will most likely not remove the lock.

You can do it, using this link:--> https://www.att.com/support/contact-us/

or:--> https://www.att.com/support/wireless/?source=EAAMO86150000000E&wtExtndSource=CORD_C005EH

or:--> https://www.att.com/device-support/selector

Regards

Giulio