What version of Finale are you using? What is your operating system? What steps did you use to try to create an MP3 file?

(There is a Quickstart video called "Create an audio/MIDI file," and there is a chapter on Sharing Your Music > Exporting an audio file in the Quick Reference Guide. These are hidden in the Help menu. Searching for Audio track in the help section also brings up instructions how to record an audio track into Finale.)

Thanks so much for responding.I should have asked much sooner.  My mac system is OS Sierra and I have the Finale 2014.5 version. The steps I took for mp3:

1. Created an AIFF file by going to “Export” > “Audio File"
2. Opened iTunes, Clicked “Import” and found the file popped up (in your Finder)
3. Found the file in "Recently Added"
4. Selected the file
5.  "Create New Version" then "Create MP3

The Finale files are going through to the receiver, the problem is that the audio track using my real voice I have recorded inside of Finale is getting bounced, and the instrument only part of my file is going through.

I suspect that the audio file you added to Finale may only be linked in, not included in the Finale music file itself. If you have not already, use the "Submit a request" link above and specifically ask whether Finale has the ability to incorporate a user-generated audio track into a WAV, AIFF, or MP3 audio export.

If not, you may have to use a DAW (there are some that are free--perhaps a version of Logic or Garage Band on your Mac) to combine the tracks and export from there.