Your chances of getting an answer will improve if you move the question to the Cocoa Touch section of the forum, which covers iOS development. You posted this question in the Cocoa section, which is about Mac development.
That's one thing to save files in the document Folder (which is part of your app sandbox) and make them visible in the Files App (and potentially prone to deletion).
If you don't want your files to be visible from the file app, do not make them visible, by setting properly some info.plist keys.
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