cellular phone service transfer
old phone is a iPhone 7 with no sim card, my new phone is a iPhone 12 max with no sim card. was able to transfer all data and pictures to the new phone but the cell service did not (new phone has the SOS on the upper right corner). my old phone's iOS is 15.8.3 and my new phone's iOS is 18.1.1 how do I get my cell service to the new phone. my carrier is AT&T
iPhone 7, iOS 15