These steps will guide you through setting up Yubico Yubikey as a second authentication factor for locize.
Go to the corner menu (your avatar).
To Enable Yubikey click on the "ENABLE YUBI" menu item in the Two-factor authentication card.
Insert the Yubikey into your workstation and touch or press the Yubikey button. This will inject the Yubikey ID.
When successful you will see the greed circle.
Upon logging in, you will be prompted for the Yubikey Security Code.
Insert the Yubikey and touch or press the Yubikey button to inject the security code.