aptsh: 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/aptsh - from package: aptsh

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

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