Install libpam-mklocaluser by entering the following commands in the terminal:
sudo apt update sudo apt install libpam-mklocaluser
Configure PAM to create a local user if it do not exist already
When the user log in for the first time, a local user is created in /etc/passwd and primary group created in /etc/group, and a local home directory is created in /home. This is useful on roaming computers when the password is set up to be cached by for example libpam-ccreds or sssd to allow login without network connectivity using the password provided by a network authentication service like Kerberos or LDAP.