Use APKPure App
Get 한게임 OTP old version APK for Android
Hangame OTP makes Hangame ID more secure.
After entering your ID and password, you will receive an authentication notification sent to the Hangame OTP app on your registered mobile device.
This is a double security service that allows you to log in safely.
More details can be found on the Hangame website.
(https://accounts.hangame.com/security/otp/home)