radexample: 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/sbin/radexample - from package: libfreeradius-client-dev

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