I’ve been using Audacity with no problems for about 10 years. Just installed it on my new Windows 10 PC and can’t export mp3 files, it keeps asking for a lame extension however when I follow the download link it takes me to a page which reads as per the text below and therefore doesn’t offer a download and installation option:
LAME is now built-in as part of Audacity
The software patent on LAME encoding library has expired, so now the LAME library for MP3 export is built-in with Audacity for Windows.
Audacity 2.3.2 is a major change from earlier versions. It’s a 64-bit app now, so computers will stop complaining about that and, as above, it has the MP3 software built-in.