pwrkap_cli: 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/pwrkap_cli - from package: pwrkap

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