Best fromm Friend Subscription :
If you wish to change the card registered for auto-renewal, you must first cancel the auto-renewal of your current Best fromm Friend subscription, delete the card registered in fromm Pay, and then re-register the new card. You can change fromm Pay by clicking on "Change" in fromm Store > Menu > fromm Pay.
In-App Subscription :
You can change the payment method through the current app market.
Apple App Store: [Apple Support Center] (https://support.apple.com/ko-kr/HT201266) Change Payment Method Change
Google Play Store: [Google Support Center] (https://support.google.com/googleplay/answer/4646404) Change Payment Method