The binary of this project is deployed at ftp://ftp.yasio.org/

Goto the parent project's root directory, the parent project is: yasio

cmake -B build
cmake --build build --config Release --target ftp_server  

Continue run ftp server after build finished

cd build/examples/ftp_server  
./ftp_server <path-to-wwwroot> <wan_ip>[optional]  

ftp://ftp.gnu.org/
https://tools.ietf.org/html/rfc959

Some client's ip may block by server firewall strategy, please switch to mobile cellular network and try access the ftp again.