Webnovel.com, formerly Qidian International, has a mixed reputation, but they do have a section for officially licensed Korean romance. They use a freemium model with daily passes and coins, which can get expensive if you’re impatient. The upside is a huge library; the downside is the pricing strategy and some community translations that vary in quality.
I’d only use it for series you can’t find elsewhere. Always check if a story is marked ‘Official’ to be sure. It’s a legal avenue, but not always the most reader-friendly compared to a flat subscription.