You'd likely be a scriptwriter. It really depends. If someone has someone else ghostwrite them a book (this is super common), are they still a writer? No. Are

You'd likely be a scriptwriter. It really depends. If someone has someone else ghostwrite them a book (this is super common), are they still a writer? No. Are they an author? Maybe. Are they just a brand slapped on the cover to shift units? Yeah, pretty much.