ap-auth: 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/ap-auth - from package: ap-utils

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

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