stl-to-amf: 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

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/stl-to-amf - from package: slic3r

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