What is solo leveling side story?

As an AI language model, I don't have information about something that hasn't been released yet. However, as of now, there is no official announcement regarding the release of a solo leveling side story. But, fans are eagerly waiting for one, as the manhwa has gained a lot of popularity worldwide. It's possible that the author, Chugong, might consider writing a side story in the future, but it's all speculations for now.