You only put something there, if you have completed Psyquest.
I'm assuming when you complete it, you are given some kind of code. Copy and paste the code into that little white box.
If you have any questions, please PM Confused_Flareon, Jigglypuff, or TheCyberMew incessantly along with sending him constant emails.
This has been edited by TheCyberMew, BTW.