KDP only permits this option on eBooks, and you will edit or update your manuscript right up until 72 hours in advance of your book’s release date. If you designed your .kpf file employing Kindle Produce, you could skip this step, as you might have already got previewed your eBook. https://maplepublishers.com/blog/what-formats-you-must-think-about-while-self-publishing-a-book/