Adds Suspend, Restart, and Power Off buttons to the GNOME lock screen (the active-session unlock dialog), so you can suspend, reboot, or shut down without unlocking. The same actions can optionally be shown in the top-right system menu (Quick Settings row, panel icon, or submenu; off by default). Actions go straight to systemd-logind; a confirmation step guards against stray clicks. Each action and placement can be toggled in preferences.

Extension Homepage

https://github.com/blurayne/gnome-shell-shutdown-options