sidekiqctl: 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/sidekiqctl - from package: ruby-sidekiq

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

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