qtcreator.sh: 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/qtcreator.sh - from package: qtcreator

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