I'm with Clinton - FTP is the easiest way to do this. However if Trellix has a file manager as part of its makeup, you can use that to upload the sound file. Then you need to create a link to it on your main page or subpage, depending where you want it. Generally, your main page has a location something like "url"/index.htm, and sound files can either be stored on that page or (to me, preferably) on a subpage souch as 'audio.' So, if you had a sound file called 'sound.wav' your link to it would be '"url"/index.htm/audio/sound.wav'. Of course, "url" above refers to the locator actually assigned to your page.

With an FTP program (there are a number of free ones available), all of the above is accomplished by looking at your page as a subdirectory on a server (which it actually is), then creating the needed subdirectories and copying the sound files to them. I assume you already know how to create a link, so I won't go into that.