1. Log in to your site editor and go to Books.
2. Select the book you want to edit.
3. Click the Retailers tab above the book cover.
4. Under External Retailers, select 'Use custom options'.
5. Edit, remove, or add retailer links.
6. Check “This is an affiliate link” if applicable.
Be sure to save changes both in the purchase links section and at the bottom of the page.
Learn more about setting up your books on your website here!