I use the Windows version, not the Mac and there are differences, so I can try to help only from my experience and the BIAB for Mac manual. BTW, you don't mention which version, i.e., year+build that you have and that sometimes can be important.

I'm pretty confident that both will output MIDI to a external hardware MIDI player.

First, there's a tutorial +++ here +++ that may help. The title may mislead a little, but it does cover external devices.

Try here in the BIAB for Mac 2023 manual:
Basic MIDI setup is on p9; more detail on page 268 (Chapter 14).

Jazz relative beginner, starting at a much older age than was helpful.
Kawai MP6, Korg M50, Ui24R, Saffire Pro 40.
AVL:MXE Linux; Windows 11; Win8.1: Scarletts
BIAB2022 UltraPAK, Reaper, a bunch of stuff.