Install libpam-oath by entering the following commands in the terminal:
sudo apt update sudo apt install libpam-oath
OATH Toolkit libpam_oath PAM module
The OATH Toolkit makes it easy to build one-time password authentication systems. It contains shared libraries, command line tools and a PAM module. Supported technologies include the event-based HOTP algorithm (RFC4226) and the time-based TOTP algorithm (RFC6238). OATH stands for Open AuTHentication, which is the organization that specify the algorithms. For managing secret key files, the Portable Symmetric Key Container (PSKC) format described in RFC6030 is supported. . This package contain a PAM module to authenticate users against a local file-based OATH database.