Very nice. Just fix the .zip because the "Kaguya" folder should be inside C:\Users\"User"\Documents\Assetto Corsa Competizione\Customs\Liveries.
In the .zip file, there is Customs, and then inside that Customs folder we got another 2 folders as said: "Cars" and "Kaguya". Just make a "Liveries" folder inside that "Customs" folder so it turns into a click and drop file. If you don't put the "Kaguya" folder inside the "Liveries", the car livery will not load at all.