I dont see the Add Version info screen. Where can that be found?

I am unclear on how to update my book. When I click on publish (which is step 3: Click Publish in the iBooks Author toolbar, or choose it in the File menu.), I am lost. Where would I find the Add Verison Info Screen that is explained in the directions provided by Apple?

This is what I'm refering to:

(copied and pasted from the orginal post)

Publishing an update:

Before you can publish an update to your book:

• You must have a Paid Books Account or Free Books Account.
• You must have submitted your book to the iBookstore at least one time.
• iTunes Producer must be installed on your Mac.

When you are ready to publish an update to your book:

1. Open the book (.iba file) you'd like to update in iBooks Author.
2. Make the desired changes to your book.
3. Click Publish in the iBooks Author toolbar, or choose it in the File menu.
4. Follow the prompts until you reach the Add Version Info screen.
5. Select the option that says "This is an update to a previously published book."
6. Click Continue.
7. Choose which of your previously published books you'd like to update, and enter a new version number.
   Note: The version number of the update must be higher than the version number that currently appears on the iBookstore.
8. Click Continue, and continue following the prompts.

iBooks Author will export your updated book for iTunes Producer. Follow the on-screen instructions in iTunes Producer to finish publishing your updated book to the iBookstore. Most of the required fields will be filled in for you, but you will need to include text in the "What's New" field to update your book.

Note: Your book’s file size cannot be larger than 2 GB.

Note: You cannot update the screenshots that appear with your book in the iBookstore via a redelivery. You can only add screenshots to iTunes Producer the first time you publish your book. If you wish to amend your screenshots, use Contact Us in iTunes Connect.