kaptain: 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/kaptain - from package: kaptain

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

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