Install libpam-snapper by entering the following commands in the terminal:
sudo apt update sudo apt install libpam-snapper
PAM module for Linux filesystem snapshot management tool
Snapper is a tool for Linux filesystem snapshot management. Apart from the obvious creation and deletion of snapshots, it can compare snapshots and revert differences between snapshots. In simple terms, this allows root and non-root users to view older versions of files and revert changes. . This package contains the PAM library for snapper, which allows the administrator to take snapshots when an user logs in or out of the system.