Changing apple id
My current apple id is a 3rd party email. I thought I set up an @icloud.com email to change it to. When I try to delete the 3rd party email address on my Iphone and change to the @icloud.com email address I get this message: "Could not update email. You can only add the @icloud.com address that is already on file in your account." I thought I was using the address that is already on file in my account. I don't see any other accounts in my file.I do see that it shows my @icloud.com as an alias. How do I change this?