After some initial confusion (myself fault) I finally understand how it worked and it's very good!
The confusion was that I've entered the "Secret" in the Profile page, but then I was thinking that I had to enter the "Sequence Key"... in reality I needed to enter the "Secret", then go to the end of the page and click on the "Update Profile"... and the "Sequence Key" is automatically created.
The second confusion was that I only need to copy the "Sequence Key" to the GRC web page, and update the Sequence Key created by the web page by the one show at the profile... but I was also entering the "Secret" in the third option of the "Passcode character set:" (called: Provide your own passcode alphabet of any composition and size:) and the correct option is let the default option... because that part is what the system is using to show in the card it self (the letters, numbers and symbols).
I should read better the instructions :p
Also... if you chose more "Length" don't forget to also to update the "Passcode length" on the GRC web page.