There's no special functionality for that. Only protocol that specifically supports setting hidden attribute is SFTP version 4 and newer. But this version of the protocol is sparsely supported.
- martin
Before posting, please read how to report bug or request support effectively.
Bug reports without an attached log file are usually useless.
how can I upload a hidden file and keep the settings as "hidden"?
After uploading such a file, it gets visible.