The Book of Revelation ends at chapter 22. Or does it?

REV. 23 is the hitherto unpublished last chapter of the Book of Revelation as dictated by St. John the Divine and transcribed by Cerise Lim Jacobs. It narrates the last battle to recapture Paradise-on-Earth and restore the balance of good and evil to our world. Persephone, the only being able to pass freely between Hell and Earth, is recruited by Lucifer in the fight against the rulers of Paradise-on-Earth. No one is exempt from this battle. Which side are you on?

[source: http://www.whitesnakeprojects.org/productions/rev-23-boston-2017/]