Unable to sync local files to ipod touch

[pugsy800]

I have local MP3 files that show up under "local files" in my spotify desktop app. I made these files part of a playlist and made this playlist available offline on both my desktop and my ipod touch, but am still unable to lay them on my ipod touch. My ipod never shows up under "Devices" in my desktop app, even when it is connected to the desktop with a USB port (I have tried disconnecting and reconnecting it), so I believe this may be the problem.