how to make appimage file executable?

I’m trying to install balena-etcher using appimage file but I don’t see the option to make it executable inside permission tab in properties

Go to terminal and change your current directory to downloaded path,
and execute following commend,

$sudo chmod +x balenaEtcher-1.5.101-x64.AppImage

then,

$sudo ./balenaEtcher-1.5.101-x64.AppImage