The old Garmin Communicator web browser plug-in no longer works with the Edge browser in Windows 10.
Most modern browsers have discontinued support for plug-ins like this.
Old Internet Explorer is still there, hiding behind the sofa ( Type "Internet Explorer" in the search box beside the start button ), and it will probably still work with the plug-in.
Personally, I would download the tracks etc and either manually place them on the device or more usually load them up into Basecamp or Mapsource for inspection, and then use their 'Send To Device' function.