Why cannot add characters?

[Sergi]

In a book of my own, I can edit the "book setting", but clicking on "characters" takes me to the index page of goodreads.com

These are the characters I wanted to add:

Erico Lombardo, Paula Vela, Anette

Is there any way I can do it? Or any reason I cannot?

[Melaslithos]

Some edits only a librarian can do. I'm not sure about characters, maybe it's the case for them.

Anyway, I added them for you.