I just started a new nextjs project with i18n config, but if I try to access the localized page, it shows 404 error.
next.config.js

  i18n: {
    defaultLocale: "en",
    locales: ["en", "ko"],
  },

I have not added any other code and just visited the homepage
localhost:3000/ - shows the correct page
localhost:3000/ko - shows an error

added info:
I'm using the app/ folder here. Does i18n work on app/ or just on pages/ ?

am I missing something here?