Open the book, then choose File > Publish to Apple Books (from the File menu at the top of your screen).
Click Continue in the Publish Your Book dialog.
Enter the sign-in information for the Apple Account that’s associated with your iTunes Connect book publishing account, then click Next.
Select “This is an update to a previously submitted book,” then click the pop-up menu and choose the book.
Accept the suggested version number or enter your own, then click Continue.
If you’re updating a previously published book and want to let readers know what’s new, enter that information in the What’s New in This Version text field.
Make any other necessary adjustments to the book information, then click Continue.
Click Upload.
When the book is successfully uploaded, you see a prompt to finish publishing with iTunes Connect.
Click Go to iTunes Connect.
The iTunes Connect page opens in Safari.
Enter the sign-in information for the Apple Account that’s associated with your iTunes Connect book publishing account.
Select My Books on the iTunes Connect page, then select the book you submitted.
The book metadata and other information you entered appears on the summary page.
If you need to adjust the rights and pricing, click Add New Territories and make adjustments.
When you’re finished, click Done.
Your book must be reviewed and approved before it’s available on Apple Books. You can check the status of the book in My Books on iTunes Connect.
For more information about publishing to Apple Books, see Intro to creating a book in Pages on MacCreate a table of contents in Pages on Mac