nfc-mfultralight: 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/nfc-mfultralight - from package: libnfc-bin

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