How do I change iTunes' default sign in info?
Apple made me change my apple id to an email account ages ago. But every time I open iTunes have to manually replace the old id and put in the new one plus the password. I've run around the Apple Support but it keeps taking me to the same page which doesn't help.
MacBook (Retina, 12-inch, Early 2015), macOS High Sierra (10.13.6)