owftpd: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/owftpd - from package: owftpd

You may install the required package with command apt-get install {package}
Error in other languages:
owftpd: bevel nie gevind nie
owftpd: comandă negăsită
owftpd: comando não encontrado
owftpd: commande introuvable
owftpd: command not found
owftpd: käsku ei ole
owftpd: không tìm thấy lệnh
owftpd: komanda nerasta
owftpd: Kommando nicht gefunden.
owftpd: kommandot finns inte
owftpd: komut yok
owftpd: nie znaleziono polecenia
owftpd: níor aimsíodh an t-ordú
owftpd: no se encontró la orden
owftpd: no s'ha trobat l'ordre
owftpd: opdracht niet gevonden
owftpd: parancs nem található
owftpd: perintah tidak ditemukan
owftpd: príkaz nenájdený
owftpd: příkaz nenalezen
owftpd: команда не найдена
owftpd: командата не е открита
owftpd: 命令找不到
owftpd: コマンドが見つかりません