exporting a audio file to mp3

Hi, I edited an existing mp3 file on Audacity and exported audio as mp3 to desktop on my Mac OS X El Capitan 10.11.3, and the Audacity is 2.1.3 version. I had to download the Lame… plugin to Applications to do this, but everything seemed okay. But when I burned this file onto a CD, it won’t play in a portable CD player, only plays on the computer?? What did I do wrong?

When making an audio CD, it’s best to export as WAV rather than MP3.
For an audio CD that will play in most CD players, you need to select “audio CD” as the type of CD (not a “data CD”).
This tutorial should be helpful: http://manual.audacityteam.org/man/burning_music_files_to_a_cd.html