ftpls: command not found

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/ftpls - from package: ftpcopy

You may install the required package with command apt-get install {package}

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