Install sddm-theme-lubuntu-chooser by entering the following commands in the terminal:
sudo apt update sudo apt install sddm-theme-lubuntu-chooser
Description:
'Lubuntu chooser' theme for SDDM X11 display manager
Lubuntu chooser theme for SDDM
Homepage: https://launchpad.net/~lubuntu-desktop
Version: 0.71
Section: universe/x11