pybit-client: 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/pybit-client - from package: pybit-client

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

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