connmanctl: 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

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/sbin/connmanctl - from package: connman

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