host ftp server on Mojave
Removed by Apple

Apple removed the included File Transfer Protocol (FTP) server from recent versions of macOS. FTP is not secure by default and better avoided.

FTP is not secure because the connection is not encrypted. Modern network protocols are encrypted by default – even on local networks.

Replacements and Alternatives

If you need to regularly transfer files, consider Syncthing. Otherwise, installing and running your own ftp server is still possible through projects like brew.

See quick to install and set up FTP server on homebrew for macOS
 for various ftp server choices.