It is indeed the event that Ro-XX-lis holds every year. It is not an official competition run together with a local government.
Since they recruit only through SNS, I am sharing this in case many people miss it without knowing.
This year I could not go to Seorak either, so I have worked up the courage to try it for the first time. If you have been waiting for it, take note~~
(It seems they are considering converting it into an official competition from next year, after taking feedback from this year's participants)