What Is The Key For Free Trials On Nick Arcade I Got The ICarly IDream In Toons Game On Nick Arcade, But It Keeps Asking Me For A Security Key, What Is That?

I got the iCarly iDream in Toons Game on Nick Arcade, but it keeps asking me for a security key, what is that? - what is the key for free trials on nick arcade

I am so confused. This is certainly a free trial and membership. Oh, and I buy the game, such as Best Buy? Answers, please!