Assuming that you need to copy images to your WP media library from other folders on your server.
You can do this with Add From Server plugin.
After installation, go to the Plugin interface and click on Add From Server > Import Files
You can also do this with admin sidebar going to Media > Add From Server.
Using this plugin you can select your folder where your images are located on the server and import the files you want into your media library.
Select all, or as per your preferences and import to library.