Just by clicking the button, you are able to choose between Korean and English version.
I probably didnt explain correctly, I wanted to register on the tpct.io website, there is a login tab and when I go, a window pops up on the Korean version of the site, although I choose English.
I then briefly looked, and now I see that the registration will still not work, it's probably a demo version.
It was just interesting to look at the private office.