That’s correct: there is no direct note input where you tap with your finger or Pencil or write with your Pencil on the score itself. If you’re looking for handwriting input where you actually write the music out longhand and have the software interpret it, you’ll need another app (StaffPad, NotateMe, Notion, Symphony Pro all provide this feature, either built-in or with an in-app purchase, and your mileage will vary in terms of how well it works for you).
We are certainly thinking about how we can make practical use of the Apple Pencil as an input device in Dorico for iPad, but I can tell you now that handwriting the music long-hand is not something we plan to work on.