The Start Page setting is located on the Book Details page. Here's how to access that page:
Open your book in Atticus.
In the top menu bar next to your book title, click “Edit Book Details.”
This will take you to the Book Details page, where you can access various settings and options related to your book including the Start Page.
While the Start Page settings you choose in the Book Details section of Atticus will be programmed into your ePub file, it’s important to note that some retailers or devices may override or ignore these settings. For example, Amazon uses its own algorithm to determine the start page when an ePub is published through Kindle Direct Publishing (KDP). Unfortunately, this means the start page Amazon selects may not always match the one you’ve set in your ebook, and we don’t have control over how they handle that aspect of the file.