Saving a file using Export but can't get MP3

Using Audacity 2.1.1 with macOS Sierra Version 10.12.6.
I have recorded a song. Trying to save the file using Export. Have downloaded and installed libmp3lame.dylib but my Macbook finder does not find an executable file and the Audacity program does not locate it to save the program to exportable format. What have I not done properly?

First, please upgrade to the latest version of Audacity - version 2.2.1, available here .

Second, use the LAME installer (the DMG), not the ZIP file. The installer will put LAME in a place where Audacity can find it.

– Bill