This is a fork of Discover's (formerly known as Muon) notifier plasmoid which you can find here. This fork aims to open the terminal with apt full-upgrade instead of launching plasma-discover --mode update. This could eventually get merged upstream as a config option (textfield with a few presets).
In order for the konsole to open the upgrade scripts correctly, they need to be executable. The ./build script uses:
chmod +x package/contents/scripts/updatepackages
chmod +x package/contents/scripts/upgradepackages