Changing iPhone

My friend has recently purchased an iPhone 12 mini from one of the distributors in Azerbaijan, Baku. But after a while, there were some problems with the screen. So he went to the store and wanted to repair it since it has garanty. He was told that there are such problems in most of the consignment of iPhones and it could take roughly weeks to check it. So since we don't have oficcial Apple stores in here, is it possible to give his phone to his relative who is goint to fly to Dubai. So he could give it to Dubai's Apple Store and change it. Or must he be there in person?