Help to export MP3 in version 2.4.2

Sorry to be using Google translator.
I have a question with version 2.4.2
In the previous version I select a song from a selection and export it in MP3 format. OK.
In this version 2.4.2 I select a song and when I’m going to export the system exports all the songs in the selection. If I use export audio, the system will export only the music I selected, however, in WAV format, not MP3.
Does anyone know how to tell me how to do it?
Thank you.

“Export menu > Export as MP3”

Thanks Steve,
The problem is that this menu item, Export MP3 does not export only a single selected song, but the entire selection.

Perhaps you want “File menu > Export > Export Selected Audio” (

Thanks, Steve