If you don’t have a book proposal to upload, you can simply select “No” on this question and fill in the fields that appear asking for a brief overview/summary and marketing/promotion plans.
However, while these are the most important elements we’d like to consider at this time, book proposals usually include more details.
There are a lot of excellent articles and resources online to help you shape your book proposal, considering the sections to include and how to present the strongest case for your book. Writer and publishing expert Jane Friedman posted a useful article on her website.