Download otpTOK for Linux. It is very important that you verify that it is the original using SHA-256.

Verify original:
sha256sum downloaded_file

SHA-256: 84708f70adb9e1cf3a960692fffd5211fcde983bfb9bb8ac78dbaa8206a077e9

It is very important that check supported operating system versions at https://otptok.com/downloads before using the application.

Then unzip the file and follow the steps in README.txt.