Unfortunately, we must comply with the validation system according to Korean law. TT
First, you should check this option as ‘외국인(foreigner)’ and input below information.
If you don’t input your name and mobile phone number correctly,
you’ll see the message '입력 정보를 다시 확인해 주세요(Please check the information is correct).
You can validate your developer account with your own mobile phone number.
That message will be shown when your mobile’s user name is not your name.
The system checks the user name of the number. Please be sure whether the user name is same with your name.
++ And the mobile should have a Korean number due to the system.