If I’m understanding your use case, you want to have a public link to a file but not allow anyone to duplicate it. If so, then I think you need to be on a Professional or higher plan so you can uncheck this option (see picture) in the Share menu. I think this option is only for files inside a project, and not for files in your drafts.

Thank you so much!

That was exactly what I was searching for.

I also have the same problem, for the solution, I just provide “can view prototypes” in this file access option