How do I delete a random private relay hidden email address which was automatically created between Apple and App which I use?

Hello, this is a strange request which I really hope someone can help with as I have spent hours trying to do this.

I want to delete the randomly produced private relay email address which was automatically created when I first signed into an App using “continue with Apple”

This is a different type to the ones which I can create myself (which have three words and can be deactivated by myself), but has a series of random characters in front of the private relay.appleID.com

i.e f4zg5p5n4c@privaterelay.appleid.com

I have checked with the Helpdesk of the App (Poe AI) I am using and they say that this comes from Apple and they cannot help me.

If I cannot do this myself, can anyone please provide details of how I may request this directly from Apple, as numerous calls to Apple support have been fruitless.

I found this on the Apple Developers Website:

To facilitate communication between users and developers, Sign in with Apple gives users the ability to use an anonymous email address. When a user provides such an address to your app, the private relay email service routes all emails between you and the user. A private relay email service sends email to a recipient using an automatically generated email address. This hides the real email address to preserve privacy.

Thanks

Ian