We finally entered after 20 minutes. It would have been convenient if I had been guided to check the text message on how to participate before entering the lecture. You don't have to refund it. I've been looking forward to this lecture. However, I checked the mail and the kakaotalk. I wonder if you could at least send me an e-mail. In this process, there is no way to inquire, and please check the comments after 20 minutes... I'm not happy to take this course. 😥