Where to try Songpyeon?

I have one more question related to Chuseok. Where can I find authentic Songpyeon? I'm not visiting any Korean families for the Chuseok but everyone was telling me that I should try good ones unless it'll ruin my image of Songpyeon 😂 So where's a good place to visit? Should I just find it on Coupang as always? Should I go to 남대문시장? (I have plans to go nearby during Chuseok) Any recommendations would be great!