Install libnss-sss by entering the following commands in the terminal:
sudo apt update sudo apt install libnss-sss
Nss library for the System Security Services Daemon
Provides a set of daemons to manage access to remote directories and authentication mechanisms. It provides an NSS and PAM interface toward the system and a pluggable backend system to connect to multiple different account sources. It is also the basis to provide client auditing and policy services for projects like FreeIPA. . This package provide the nss library to connect to the sssd daemon.