itch.io

I had a pretty hard time with that too, basically you need to put the unzipped folder into the "game" file within the regular "14 days with you" folder, then unzip it. although it can vary based on what computer you're using. also just wanna note that there may be some scenes missing, as I had trouble with that the first few times I tried installing the folder, but I think its fixed. basically, you make sure you have the original 14 days with you game on your computer, for me its "14DaysWithYou-5.5-pc", next make sure you have the unzipped download of the "14NightsWithYou-paid" or "14NightsWithYou-free" and drag and drop it into the "14DaysWithYou-5.5-pc" then when you click into the same file, you should see, "14DaysWithYou" (the game application), "14DaysWithYou.py", "14DaysWithYou.sh" and then the "game", "renpy" and "lib" files, drag and drop the "14NightsWithYou-paid" or "14NightsWithYou-free" files into the "game" file, enter into the "game" file, and unzip the  "14NightsWithYou-paid" or "14NightsWithYou-free" file, from there you can start the game as normal,  look up to the top right corner, you should see "[DLC] 14 Nights With You (PAID)" or "[DLC] 14 Nights With You (FREE)", then enter the 14DaysWithYou section in the game and on the bottom right corner in the "bonus" section, enable the DLC. Hope this helps!