앱아이디 - 846396
코드 요청받고 토큰 요청하면 400 에러 발생합니다.
grant_type=authorization_code&client_id=968e8e47909bc8f99c960bcd68b8b94a&redirect_uri=http://localhost:7777&code=Iglq4MqaE4gi8RFm8Ud6n0oGSIdtHqsPECzvyoazKwUR0IuPCrPGUrxVx71pihpcJeO-tAopyNgAAAGFeqEy_g
responseCode : 400
java.io.IOException: Server returned HTTP response code: 400 for URL: https://kauth.kakao.com/oauth/token