I need give permission to users to access folders and files on QNAP, so they can edit, save and create new without allowing them to use the QNAP interface. is that possible? and how?
From Windows, use the file manager to set up a remote connection to the NAS device
Windows Explorer
-> Computer
-> Map Network Drive
Use that users NAS credentials to log into the NAS.
From MAC, use Finder to set up a share or use Finder to set up AFP share. Again, log in using the users NAS credentials.