If you do not have a NAS volume created, you'll need to create one. To create a volume, click the "File System" tab, and then right-click "NAS Volumes" and select "Create NAS Volume".
Name the volume, and set the size of the volume. Then select "OK" to create the volume. Now, to set up your SMB share, right-click on "SMB Shares," then select "Edit SMB Home Share Settings".
Check the "Enabled" box, then click "Change" and choose the NAS volume you would like to use, then click "OK". From here, click "Apply," and then "OK".
You must do this before any other options may be configured. Next, you need to check your security settings by going back into the "SMB Home Share Settings".
Confirm that "Access Based Enumeration" is enabled to prevent users from seeing folders and files they do not have rights to. Click "Apply," and then "OK". Here you can see an overview of your SMB Home Share.