What is the syntax needed in the CLI to assign permissions to an SMB Share?

I tried to assign permissions to a newly created SMB share, but the Isilon can't find my AD Account

isi smb shares permission modify testshare --user="DOMAIN\testuseraccount" --permission-type=allow -p=full

User DOMAIN\testuseraccount not found in permissions list.

I can use the WebUI to complete the same task, but I have to put in my [Access Zone, Provider, AD Domain] before my AD account will show up. I'm sure I have to do the same thing the CLI, but the Help menu only shows how I can specify a --zone, which I have tried and it gives the same "not found in permissions list" error.

Ironically, if I use the WebUI to add the AD user with permissions to the SMB share, such that the user shows up using the command

isi smb shares permission list testshare

I am then able to use the Modify command to tweak with the permissions [root, read only, write]

isi smb shares permission modify testshare --user="DOMAIN\testuseraccount" --run-as-root