-a tells the FileZilla client where local files work should be done. IE: it's where files should be downloaded to or uploaded from by default (if no specific paths are used in the transfer ccommand itself).
It's expects a path to a folder.
From FileZilla docs:
Sets the local site (left-hand side) to the given path.
Use double quotation for paths with spaces in them.
FileZilla isn't intended to be scripted (their goal is to be a GUI client), so there's no way to specify files to transfer from the commandline.
Perhaps look into using Windows' in-built
FTP.exe for scripting.
Transfers files to and from a computer running an FTP server service
(sometimes called a daemon). Ftp can be used interactively.
FTP [-v] [-d] [-i] [-n] [-g] [-s:filename] [-a] [-A] [-x:sendbuffer] [-r:recvbuf
fer] [-b:asyncbuffers] [-w:windowsize] [host]
-v Suppresses display of remote server responses.
-n Suppresses auto-login upon initial connection.
-i Turns off interactive prompting during multiple file
-d Enables debugging.
-g Disables filename globbing (see GLOB command).
-s:filename Specifies a text file containing FTP commands; the
commands will automatically run after FTP starts.
-a Use any local interface when binding data connection.
-A login as anonymous.
-x:send sockbuf Overrides the default SO_SNDBUF size of 8192.
-r:recv sockbuf Overrides the default SO_RCVBUF size of 8192.
-b:async count Overrides the default async count of 3
-w:windowsize Overrides the default transfer buffer size of 65535.
host Specifies the host name or IP address of the remote
host to connect to.
- mget and mput commands take y/n/q for yes/no/quit.
- Use Control-C to abort commands.