You need an embassy visa for Eswatini if you have a South Korean passport
Visa options for Eswatini
Visitor visa
Travelers need a visa to visit Eswatini for Business or Tourism. A paper or embassy visa is the only visa available for travelers visiting Eswatini. The visa is typically a stamp or sticker added to the passport. Travelers must obtain this visa from a local embassy, consulate or visa center before traveling.