autopasswd: command not found

Have You tried accessing the binary with the full path?

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/autopasswd - from package: expect

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