lnpd: 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/sbin/lnpd - from package: lnpd

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

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