nxt_push: 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/nxt_push - from package: python-nxt

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

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