Libraries placed in root are not detected / only inside "modules" folder

Hello, I hope someone will help. I have a problem with the libraries API module: I can install the module correctly inside the module folder, then place the folder with external files inside, I name it like it should be named, but nothing is found in the site when I check. I have also tried switching the theme to Bartik, but I still have the error. If I put the module in the root, then Drupal won't even detect it and I could not even enable it. What could be the problem? Thanks