aptly: 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/aptly - from package: aptly

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