fzputtygen: 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 CentOS possible default full paths are:

/usr/bin/fzputtygen - from package: filezilla

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/fzputtygen - from package: filezilla

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

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