flrig: 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/flrig - from package: flrig

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