You choose your own secret word the first time when you log on ur acc on site. If you forgot it write to support but for your good write it down somewhere for next time
We waren`t here logging in on the site when secret word was implemented, and the first time we logged in since we came back we were asked to say what the secret word was, not to set it up.
After I wrote to support they reset it, and I got to set it by myself. I`ve got it written down somewhere now... Sound advice