change bitrate to a folder

hi. I’m with Audacity 2.2.1

I’ve used GoldWave so far and I wanted to see what it would be like with this program.
I find to change from one to one the bitrate of each mp3 and the option to create a script and put EXPORTMP3 but I do not see the options to export:
128 kbps, 44 hz, stereo … those things … I do not see them

Thank you.

See … https ://

[ BTW, making an MP3 of an MP3 will inevitably degrade the fidelity,
even if you use a higher bitrate on the copy than the original’s bitrate ].