You can find the first chapter and subsequent volumes through the following official and licensed platforms:
Far from the surface, Light establishes his own underground kingdom, amassing power that dwarfs the nations above. You can find the first chapter and subsequent
The user mentioned it's in high quality, so the review should probably note the art quality. The chapter is called "Chapter 1 RAW", so maybe it's the first chapter of the series. Since it's a raw scanlation, the text is in Japanese, and the images might have OCR errors, but the user is okay with that. Light establishes his own underground kingdom
: The manga originally began serialization on Kodansha's Magazine Pocket website. This is the primary source for "raw" (Japanese language) chapters. the text is in Japanese