dh_aqbanking: 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/dh_aqbanking - from package: libaqbanking34-dev

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