geogebra: 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/geogebra - from package: geogebra

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