urlwatch: 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/urlwatch - from package: urlwatch

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

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