qnapi: command not found

Have You tried accessing the binary with the full path?

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/qnapi - from package: qnapi

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