changing the email address on my apple id

On the iPhone it's under Settings, tap your name at the top, then the sign-in / security section where your email and phone numbers are listed. Edit the main address there and Apple sends a code to the new one to confirm it. Two things trip people up. The new address can't already be attached to another Apple ID, including an old one you forgot about. And if your Apple ID is an @icloud.com address, you usually can't switch it to a gmail or outlook one at all. Your devices stay signed in afterwards, you just use the new email next time it asks.