Where is the bit setting?

How do I lower the bit rate from 32 bit (float) to 24 bit?

Disregard…found it

When recording, and for working in the project, it is nearly always best to use 32-bit float format.

Conversion to a lower sample format (such as 24-bit) is normally done by selecting the required export format. (see: https://manual.audacityteam.org/man/file_export_dialog.html)