I would like to be able to transfer a file using FTP from the XBEE Wi-Fi module. Is it possible to do this?
The XBee WiFi modules do not include any FTP client or server functionality in their firmware. You’d need to implement your own FTP client to be able to send a file via FTP.
You might be better implementing your own protocol to send the data to an intermediate PC/server, or using a simpler protocol, for example TFTP, that would be easier to implement.