kritasketch: command not found

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/kritasketch - from package: krita-sketch

You may install the required package with command apt-get install {package}

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