python3dm: 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/python3dm - from package: python3-dbg

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

Error in other languages:
python3dm: bevel nie gevind nie
python3dm: comandă negăsită
python3dm: comando não encontrado
python3dm: commande introuvable
python3dm: command not found
python3dm: käsku ei ole
python3dm: không tìm thấy lệnh
python3dm: komanda nerasta
python3dm: Kommando nicht gefunden.
python3dm: kommandot finns inte
python3dm: komut yok
python3dm: nie znaleziono polecenia
python3dm: níor aimsíodh an t-ordú
python3dm: no se encontró la orden
python3dm: no s'ha trobat l'ordre
python3dm: opdracht niet gevonden
python3dm: parancs nem található
python3dm: perintah tidak ditemukan
python3dm: príkaz nenájdený
python3dm: příkaz nenalezen
python3dm: команда не найдена
python3dm: командата не е открита
python3dm: 命令找不到
python3dm: コマンドが見つかりません