사용자에게 숨겨지고 API로 수정 가능한 사용자 정의 필드?

I don’t quite understand how you’d do that, but you might check out DiscourseConnect to solve that problem. Or perhaps a custom plugin (if you’re self-hosted or on Enterprise) is what you’d want.

You could populate the User Note with the API the same as what you’d do with the API.