ansi2txt: 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/ansi2txt - from package: kbtin

You may install the required package with command apt-get install {package}
Error in other languages:
ansi2txt: bevel nie gevind nie
ansi2txt: comandă negăsită
ansi2txt: comando não encontrado
ansi2txt: commande introuvable
ansi2txt: command not found
ansi2txt: käsku ei ole
ansi2txt: không tìm thấy lệnh
ansi2txt: komanda nerasta
ansi2txt: Kommando nicht gefunden.
ansi2txt: kommandot finns inte
ansi2txt: komut yok
ansi2txt: nie znaleziono polecenia
ansi2txt: níor aimsíodh an t-ordú
ansi2txt: no se encontró la orden
ansi2txt: no s'ha trobat l'ordre
ansi2txt: opdracht niet gevonden
ansi2txt: parancs nem található
ansi2txt: perintah tidak ditemukan
ansi2txt: príkaz nenájdený
ansi2txt: příkaz nenalezen
ansi2txt: команда не найдена
ansi2txt: командата не е открита
ansi2txt: 命令找不到
ansi2txt: コマンドが見つかりません