Is this separate from Novlr Studio? Yes. You use one Novlr account, then switch between the writing app and the author website surface from the chevron next to the logo.

Do I need a separate login for Sites? No. Your Novlr account is the login for both Novlr Studio and Novlr Sites.

Do Studio users pay again? No. Novlr Sites is included with Studio and Studio Lifetime.

Can I use a custom domain? Yes, custom domains are part of the paid Sites plan.