SMB permission Issue

I have an ntfs external hard connected to my rasp 3 connected to my mac via smb. I can view the hard drive and I can even drag and drop individual folders but when I use automator to automatically transfer my files to the hard drive it wont let it write. It says permission denied. I cant change the permission…it just says I have “custom permission” and doesnt give me the option to change it. Any help would be appreciated…

How is the hard drive attached by NFS? Using the kodi plug in or is it mounted using /etc/fstab?

How did you share the drive by smb? Using the OSMC app or by installing samba-server?

What user are you connecting to the RPi as from your Mac? Does that user on the RPi have write access over the NFS mount?