An addon is only available where the author wants it available. Assuming the similar names aren't a coincidence, that addon was created, or is currently maintained by, that website. If they aren't distributing the addon elsewhere, then that site is the only source.
If you can't find the addon on this website then it's obviously not posted here for download and there's nothing anyone here can do about it. If it's available only on a Korean website then that is your only option.