stpm-sign: 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/stpm-sign - from package: simple-tpm-pk11

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