FTP = file transfer protocol. You seem to have the domain host/server and URL address set up. Right? Now you use FTP to upload your files to the host/server.
At the moment, cannot find how to do it without some FTP software (there is a way). Check with your host/server to see if they have some FTP program built-in and/or what they recommend. There are some free FTP programs so do a search.
I use DREAMWEAVER to transfer files. If you have Dreamweaver, let me know and I'll try to walk you through the steps. Generally it's something like that shown in scren shot FTP.sitename.com
Cannot upload screen shot