vkeybd: 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/vkeybd - from package: vkeybd

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