Install libpam-kwallet4 by entering the following commands in the terminal:
sudo apt update sudo apt install libpam-kwallet4
KWallet (KDE 4) integration with PAM
The KDE Wallet system provides a secure way to store passwords and other secret information, allowing the user to remember only a single KDE Wallet password instead of numerous different passwords and credentials. . This package provides a simple PAM integration for KWallet, so you can log in to open a KWallet.