You can report them here! ^^ I'd also suggest skimming through the comment section in case your issue has already been mentioned and resolved.
If I recall correctly, a similar issue has been reported before, and the solution I gave was to ensure you're following the installation guide shown on this Itch page, and that you're using the correct folder name. Make sure the folder is named "14 Nights With You", and not "14nightswithyou-free" or "14nightswithyou-paid".