gbs3: 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/gbs3 - from package: gambas3-script

You may install the required package with command apt-get install {package}
Error in other languages:
gbs3: bevel nie gevind nie
gbs3: comandă negăsită
gbs3: comando não encontrado
gbs3: commande introuvable
gbs3: command not found
gbs3: käsku ei ole
gbs3: không tìm thấy lệnh
gbs3: komanda nerasta
gbs3: Kommando nicht gefunden.
gbs3: kommandot finns inte
gbs3: komut yok
gbs3: nie znaleziono polecenia
gbs3: níor aimsíodh an t-ordú
gbs3: no se encontró la orden
gbs3: no s'ha trobat l'ordre
gbs3: opdracht niet gevonden
gbs3: parancs nem található
gbs3: perintah tidak ditemukan
gbs3: príkaz nenájdený
gbs3: příkaz nenalezen
gbs3: команда не найдена
gbs3: командата не е открита
gbs3: 命令找不到
gbs3: コマンドが見つかりません