We've created this Forum Thread with some workarounds and advice to assist you in publishing you ebook.
How do I add the ISBN Barcode to Paperback book?
I have got the free Lulu ISBN Barcode while creating the ebook verson of my book, later when I created a new project for paperback I didn't get the screen to add the ISBN number (or maybe I missed it). Now the back cover of the book displays a barcode that is different from the ISBN barcode. How can I update it with the ISBN? I also can not see the ISBN number below Paperback book in my project list as it is there with eBook version.
* I have tried to revise the project but everytime the screen for ISBN doesn't show up.*
This is my project list, the first one is for Paperback copy.
This is the barcode at the back cover of Paperback book-
This is ISBN barcode -