Byte Rate Disaster

I really, really need help!!! I narrate audiobooks for the blind. I’ve been using Audacity for several years. De to what seems to have been a Windows 10 upgrade, my settings were evidently altered during the night. I’m trying to submit a story reading and the publisher’s uploader is stating I need to submit an MP3 with at least a 193 bit rate. Files uploaded two nights back were fine.

I record in wav16 / mono and then convert to Mp3.

I’ve upgraded to the latest version of Audacity, but cannot locate where to see and set bit rate preferences. Where, how do I do this?!

After upgrading to Win10 and re-installing/upgrading Audacity, you may have to re-install [u]LAME[/u].

See here for how to set the MP3 export options:

I expect that they will want the “Bit rate mode” to be “Constant”, then set the “Quality” setting to 192 or 256 kbps.
If the recording is mono, 192 kbps is very high quality MP3.

Is there any evidence that is true?