Activate Booky from your amea.space account first - you'll be asked to confirm what data it stores.
Start with the basics - you can add everything else on the next page.
Pick a field on the left and enter its value on the right. Add as many differences as you need.
Several authors possible - the first one is the main author.
If it is just another edition or version of that book (e.g. the ebook of a hardcover), switch on the slider at the top and add an edition to the existing book instead.