The administrator can enable Multi-Factor Authentication for all users in the account, as explained in the article: How to enable multi-factor authentication for the account.
If your account doesn't have it enabled but you want to add this security method for your individual user, you need to go to Profile (top right corner where your username appears) > User Settings > Security Settings > Use Google Authenticator > Enable.
After clicking "Enable", use the Google Authenticator app to scan the QR Code that will appear on the screen.
If everything is correct, after submitting the PIN, the setup will be completed and the option will display the word "Disable".
The next time you log in, after entering your email and password, the system will request the PIN generated by Google Authenticator to complete the access.