How to change your Apple ID on my IPHONE
Hello There,
I had changed my Apple ID email on the computer but my IPHONE is still showing the old email as ID and asking for password, please advise how can i put my new ID in my phone, thanks
See the Apple Support article below for where you should sign out of the old email address and then sign in with the new email address.
What to do after you change your Apple ID or password - Apple Support