Here you can set up a two-factor authentication using a Yubikey or an Authenticator app. After the activation, you will then need one of these keys in addition to the password to logon to the program, as well as to sign orders and payments. The overview displays all keys that you have set up.
By clicking on one of the Add buttons, a dialog box will be displayed, on which you can set up the respective key. This key will then appear with its ID in the overview here.
To remove a security key, mark the line in the overview and klick on Remove. Then you will be prompted to confirm the process and the key will be removed from the overview. If you only have one security key left, you can only remove it if you have allowed this in the preferences under Password requirements.