glabels-3: 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/glabels-3 - from package: glabels

You may install the required package with command apt-get install {package}
Error in other languages:
glabels-3: bevel nie gevind nie
glabels-3: comandă negăsită
glabels-3: comando não encontrado
glabels-3: commande introuvable
glabels-3: command not found
glabels-3: käsku ei ole
glabels-3: không tìm thấy lệnh
glabels-3: komanda nerasta
glabels-3: Kommando nicht gefunden.
glabels-3: kommandot finns inte
glabels-3: komut yok
glabels-3: nie znaleziono polecenia
glabels-3: níor aimsíodh an t-ordú
glabels-3: no se encontró la orden
glabels-3: no s'ha trobat l'ordre
glabels-3: opdracht niet gevonden
glabels-3: parancs nem található
glabels-3: perintah tidak ditemukan
glabels-3: príkaz nenájdený
glabels-3: příkaz nenalezen
glabels-3: команда не найдена
glabels-3: командата не е открита
glabels-3: 命令找不到
glabels-3: コマンドが見つかりません