I querried the KDP several mpnhs ago and her is how to do it!
[b] Hello John,
Author Central allows you to manage up to three Author Pages within a single account. If you write under your real name as well as a pseudonym, you can manage both Author Pages from the same Author Central account. Here's how:
1. Log in to Author Central (https://authorcentral.amazon.com).
2. Click the "Books" tab located on the top of the page.
3. Click on the "Add more books" link that appears under "Are we missing a book?"
4. Search for books written by Nom de Plume by title, author, or ISBN.
5. Click "This is my book."
Once we verify you're an author of the book selected, a second Author Page will be available for you to maintain.
I hope this helps! We look forward to seeing you again soon.