offical website link:https://play.google.com/intl/ko_kr/about/giftcards/
1.This product is applicable for Google Play KR store with Korea IP Address ONLY. It is NOTredeemable for Google Play accounts created in other countries than Korea
2.Violation of Google Play Gift Cards’ Terms of Service will result in CODE DEACTIVATION without prior notice. Kindly ensure the posting address, IP Address and account settings are in line.
3.CODE once deliver , Do not refund