Though "어서 나으세요" is also a native way to express the meaning, "빨리 나으세요." sounds more preferable to me. xD

The first one.^^/ \^o^/

There are many ways to say get well soon in Korean. The formal and most used line is 빨리 나으세요 (Palli naeuseyo) An informal way to say get well soon in Korean is 빨리 나아 (ppalri naa) Learn more ways of saying get well soon in Korean. https://koreanly.com/get-well-soon-in-korean/