mountpy: 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/mountpy - from package: mountpy

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

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