I tried to log in after setting up Login Restriction by Country, but I haven't yet received a verification message.
If you have not received KakaoTalk message or email for Additional Verification, please check the followings:

1) KakaoTalk Verification

If you're using KakaoTalk normally but have not received verification messages via KakaoTalk, check whether the account information entered for login matches up with the account information registered to KakaoTalk.
You can check contact numbers and email information in [ KakaoTalk > My Profile > Settings > Profile Management ].

2) Backup Email

There may be delays in delivering emails depending on mail service.
If you're not receiving verification email for a while, tap the "Resend Verification Code" button. It could be sorted into Spams or an Individual Mailbox. Please search by keyword, "Kakao" or "카카오," in Inbox.
If you have not been receiving verification emails from Kakao Account, please contact your mail service website to resolve this issue.