Changing my register AppleID

Before I subscribed to Fotomagico (1/26/2024), I registered my Apple ID, but my email was hidden.

I want to use my AppleID with my email and cannot register it. The system says my account has already registered with another Apple ID.

This is preventing me from using the iPad version of Fotomagico,

How can we remove the first AppleID so I can register the correct AppleID.