No, BLU has no capability to do FTP or anything having to do with the internet: you need to attach an old-fashioned serial cable, correctly wired, between your Lisa and your modern computer, then use a program like HyperTerminal (Windows) or minicom (Linux) or ZTerm (Mac) to establish a serial connection to the Lisa over the serial cable.
To download your hard drive image over the serial cable, the serial program you use must support a file-transfer mechanism called XModem, and of the three programs I mentioned, I'm not sure HyperTerminal does. (The other two have it.)
You may be able to make use of your WiFi modem, provided that the Lisa and whatever serial program you're using on the modern PC can pretend there's just an ordinary wired cable connecting the two of them.
Welcome to the pre-Web home computer communication world of the 1980s!