kgb-client: 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/kgb-client - from package: kgb-client

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

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