I don't think Ubuntu Software Center has that name for its package; when I entered the command apt search
, I didn't got that package name in the results:
$ apt-cache search software-center
app-install-data - Ubuntu applications (data files)
software-center-aptdaemon-plugins - The aptdaemon plugins for software-center
ubuntu-kylin-software-center - Software maintenance management tools
The Software Center package is named gnome-software
(if you're using the GNOME desktop) on Ubuntu 18.04
$ apt-cache search gnome-software
gnome-software - Software Center for GNOME
gnome-software-common - Software Center for GNOME (common files)
gnome-software-dev - Software Center for GNOME - development files
gnome-software-doc - Software Center for GNOME - documentation
gnome-software-plugin-snap - Snap support for GNOME Software
gnome-packagekit-session - Transitional package (gnome-packagekit-session -> gnome-software)
gnome-software-plugin-flatpak - Flatpak support for GNOME Software
gnome-software-plugin-limba - Limba support for GNOME Software
libflatpak0 - Application deployment framework for desktop apps (library)
So if you want to reinstall it, just type
sudo apt install gnome-software