Drop-in judo for kids?

Shot in the dark, but since I'm not finding much in r/judo, I thought I'd ask here. I'm visiting Seoul, and because Korea is a big judo country, my kid (who's 11) and I would like to work out while we're there.

I'm having trouble finding judo clubs that take visitors. The Seoul Y Judo Club is very welcoming to foreigners, but they don't have a kids' class. Any help appreciated!