Hey, nanjij, I got the link for you to input your clear code. Just click on the link and when you get there, click on "RETURN CLEAR CODE" and just follow the directions given on the screen. You need to register with an ID before you can input your clear code, so just follow the directions and you should be able to get registered, then be able to input your code. Hope this helped!
https://www.konamijpn.com/products/mgs2/english/mr/