kamcmd: 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/kamcmd - from package: kamailio

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

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