As of February 24th, 2021, Black Desert Online will be published by Pearl Abyss instead of Kakao, so if you want to continue your account, you’ll need to do a transfer. You can do that HERE. There are instructions for Steam users HERE. The transfer period runs January 27th, 2021–May 31, 2021.
Kakao Cash will not be transferred, so get in there and get it spent before February 24.
I have done it. Just follow the directions and you’ll be fine. Happy Transfer!