fgadm: 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/sbin/fgadm - from package: filtergen

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