If you are unhappy with the book that has been generated you can transfer your purchase to a new project and start again.
From the Order Status menu of your current book, click on How do I make changes? Then click on Create new book.
This action will keep your current book as a digital copy, move the prepaid print order (cost of producing the physical book, plus shipping) to a new editable book, and spend 25 generation credits.
Following the transfer, you will be directed back to a new book creation page, where you will be able to describe your personalized characters and upload a reference photo as well as select/edit your storyline and then generate your new book.