I'm currently in Korea for vacation and I really want to try playing on the Korean server, so I managed to get my hands on one of the beta keys.

As far as I know I've successfully made and verified a Nexon account, but whenever I try to input my Nexon DotA 2 Beta key in the login screen, I get an invalid result. Right now I'm using regular steam and simply adding -nexon to the launch options to get to the registration page.

Is there something I'm doing wrong?