I was wondering, using the built in connect() function for TCP connections, how would I connect to a FTP and write to a text file? I can’t find any good information about connecting this way.
FTP is an ancient, obsolete, and quite strange (by today’s standards) protocol. While there are Node libraries implementing it, they are unlikely to work in Workers, so you would probably have to implement the entire thing yourself. (And only PASV mode would work.)
I’d recommend using literally any other protocol. An HTTP upload would be easy, given server-side support.