I think it is not possible in https://cloud.server.tld/settings/user/notifications
I don’t think that makes sense either. What do you want to achieve? You can, for example, limit the download of files to e.g. “1” or with prior display of e.g. PDF to “2”. You can also, for example, set the authorisation to “View” and “Delete” but not “Edit” so that the recipient can delete the file themselves. The Secrets app is quite nice for texts that can only be read once. For confirm reading read maybe this thread.
What exactly do you want to achieve?