Can I use shared drafts with the API?

Anything that can be done via the UX can be done via the API. That said, I don’t believe we have this documented. You’ll need to follow this guide to figure out how to make the correct API calls.

This is expected, the shared drafts category is still a normal category, normal topics can be created there. You need to change the type of content you’re creating - a shared draft, not a new topic.