Select [Utility] - [Administrator] - [System Settings] - [Stored Documents Settings] - [USB flash drive function settings], and set [Save Document] to ON to permit saving a file in a USB flash drive. To prevent data leakage, saving a file in a USB flash drive is prohibited by default.
When user authentication is enabled, select [Utility] - [Administrator] - [User Auth/Account Track] - [User Authentication Setting] - [User Registration], and permit saving a file in a USB flash drive for each registered user.