Question about the silk road registration - PIN

Hey, I'm just getting acquainted with this Tor world and I wanted to access the silk road, so I went inside this URL silkroadvb5piz3r.onion with my Tor browser, but their asking me for a PIN number with my registration, anyone knows how to get this PIN number?

Thanks.

i don't remember very well but i think that you have to set it in your profile first