From the Producer page, you can access Book Metadata by clicking Book Metadata in the left sidebar under the title of your book.
The information you provide in the Book Metadata modal will be used in auto-generated Epub and PDF previews and exports.
You can change the Title, Subtitle, and Authors.
You can also add copyright and licence information.
When you are done inputting your metadata, click Save. You can return to the Book Metadata modal at any point to add or update Book Metadata information.