Can't publish my iBook

I got a problem and I need to solve this as soon as possible. I don't know what's wrong!

I need to publish the iBook - free to download -

When I click on "Publish" (iBooks Author), then a pop up appears and ask me to log in. Then, It says something about iTunes Connect (log in) and then nothing happens, cause' Apple Connect is already Activated, for iOS Apps, but I don't know if I need another for "Books"? I know and iTunes Connect says: "

Unable to Process Request

You cannot access this page.

The Apple ID you signed in with does not have permission to view this page. For more information about access permissions, see the Contact Us module."

PROBLEM: I get stuck on the 3th step, I can't download iTunes Producer, I don't know why, it says:

Unable to Process Request

You cannot access this page.

The Apple ID you signed in with does not have permission to view this page. For more information about access permissions, see the Contact Us module.

PROBLEM: Then, I click to continue, and ask me again for my log in details and says:

"This Apple ID isn't associated with a Free or Paid Books Account"

What can I do? What's wrong? Thanks for reading... need help!