drtext: 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/drtext - from package: emboss

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