Update Apple ID Settings

I updated to version 12 and now my phone is asking me to update my Apple ID Settings which is no issue under normal circumstances, however, the phone is showing my OLD apple id that I haven't used in years. HELP!!!! I no longer have that ID and need to remove it from everything completely.

What is confusing is that my correct Apple Id shows as the current login. I don't understand why it's asking for the old ID and it will not let me change the ID, it just asks for the password. 😕

How do I fix this?