Question Problems regarding registration in AuKor.

[-Cloud Strife]

I recently downloaded the client in clubaudition.com and tried to register there. I have already filled up the KSSN and the korean name. Then in the next page, I filled up my username, password, and some secret questions and the verification code, but I can't seem to know what will I put in the mobile number box and the address box, when I put some random numbers there, the website always gives me some sort of error or the typing cursor will be moved to the password box after pressing the confirm button. Can someone please help me with this? Thanks!

PS: If there's a guide about it already, can you link me to them? I" can't seem to find one using the search button, and other online guides are from different websites.