Sending Attachments In SmartMail

I’m trying to use SmartMail to send all files in a folder but can’t seem to get it to work using this line of code.

                -- include_files = [[{
                    -- app = AXIOS_BASE .. "\\Data\\Attachments\\",
                -- }]],

I can’t figure out what the wild card is to include all files in the folder.  If I explicitly state the file name the email with the attachment sends, but if I leave it blank or try any variation of wildcards, I just get an error Invalid email 'include_files' entry: no file exists with title.  The email still sends but no attachments.  The files can be in any format, .pdf, .xlsx, .csv, etc…

Any help would be really appreciated.

Thanks!