adding a file

I’ve got a folder at my hard-disk of my laptop, named ‘Home videos’. I’ve add thes movies to a library on the Plex. I’ve made some new home videos(5 single movies/files) and I add these one the folder ‘Home videos’ at my hard disk. How can I add these 5 new files/home videos to my library at the Plex. Or do I have to add the whole folder “Home videos” again and Plex will find out what is new. I can;t find a answer to my question/problem actually