I cannot seem to add a folder as a library

I have tried several ways of "Browsing for a folder", i create the folder with i think the right path but there is nothing there although there are 4 MP4 movies in the folder
Plex is installed on a Qnap TS251+
The path i am using is /user/williamwoodhead/desktop/movies ?????
Can anyone assist please what am i doing wrong???