ext2simg: 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/ext2simg - from package: android-tools-fsutils

You may install the required package with command apt-get install {package}
Error in other languages:
ext2simg: bevel nie gevind nie
ext2simg: comandă negăsită
ext2simg: comando não encontrado
ext2simg: commande introuvable
ext2simg: command not found
ext2simg: käsku ei ole
ext2simg: không tìm thấy lệnh
ext2simg: komanda nerasta
ext2simg: Kommando nicht gefunden.
ext2simg: kommandot finns inte
ext2simg: komut yok
ext2simg: nie znaleziono polecenia
ext2simg: níor aimsíodh an t-ordú
ext2simg: no se encontró la orden
ext2simg: no s'ha trobat l'ordre
ext2simg: opdracht niet gevonden
ext2simg: parancs nem található
ext2simg: perintah tidak ditemukan
ext2simg: príkaz nenájdený
ext2simg: příkaz nenalezen
ext2simg: команда не найдена
ext2simg: командата не е открита
ext2simg: 命令找不到
ext2simg: コマンドが見つかりません