httpfs2: 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/httpfs2 - from package: httpfs2

You may install the required package with command apt-get install {package}
Error in other languages:
httpfs2: bevel nie gevind nie
httpfs2: comandă negăsită
httpfs2: comando não encontrado
httpfs2: commande introuvable
httpfs2: command not found
httpfs2: käsku ei ole
httpfs2: không tìm thấy lệnh
httpfs2: komanda nerasta
httpfs2: Kommando nicht gefunden.
httpfs2: kommandot finns inte
httpfs2: komut yok
httpfs2: nie znaleziono polecenia
httpfs2: níor aimsíodh an t-ordú
httpfs2: no se encontró la orden
httpfs2: no s'ha trobat l'ordre
httpfs2: opdracht niet gevonden
httpfs2: parancs nem található
httpfs2: perintah tidak ditemukan
httpfs2: príkaz nenájdený
httpfs2: příkaz nenalezen
httpfs2: команда не найдена
httpfs2: командата не е открита
httpfs2: 命令找不到
httpfs2: コマンドが見つかりません