jtb: 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/jtb - from package: jtb

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

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