Audio from what source... mp3 file, youtube, CD, et?
MP3 audio-only files. I purchased a couple of audios from a site that were advertised as "downloads." When I got to my library and tried to download -- they would play on my computer, but there was no way to download for future, off-line listening.
Turns out it's another example of browser wars. The third time I went back to the site, I spotted a notice that the site is optimized for Firefox and Chrome. I don't allow Chrome on my computers, but I do have an up-to-date Firefox (although it isn't my primary browser), so I tried that. Still no joy.
So I tried Edge -- and suddenly the download icon was there, as advertised.
So the immediate issue has been resolved, but I will look into Audacity for future reference. Thanks.