This is the source. CODEX is a scene group that cracked the game's Denuvo protection.
When looking for the game, you will encounter two main terms. Here is the difference and why one might be "best" for you. yakuza kiwami update v5 codex fitgirl best
Fitgirl's version of "Update v5" is the gold standard because she verifies the MD5 checksums of every file post-install. You aren't just getting the update; you're getting a confirmation that the update installed correctly without corrupting the .cpk archive files. This is the source