Using Macbook Air 10.13.6 High Sierra Audacity 2.1.1 Lame version 3.99.5
Using Audacity with no problem --works fine but downloaded Lame mp3 and cannot locate downloaded file .
Already used 'Preferences / Libraries with no luck … could use some help with this for those in the know 
09-03-18 Note: I’ve recently seen my therapist and they suggested contacting Audacity Forum
Did it not download into your Download folder?
Were you following these instructions: https://manual.audacityteam.org/man/installing_and_updating_audacity_on_mac_os_x.html#maclame