winscp.com: logging in without using keyboard-interactive

Hello,
I'm trying to logon to sftp using one line such as username@ftp.ftpsite.com password but am unsucceful
the only am able to login successfully is typing username@ftp.ftpsite.com <enter>
and then it prompts me for password.
is there a one line command to type so that i don't get prompted for password

username:password@ftp.ftpsite.com