Uh that was very brave of you.
https://avid.secure.force.com/pkb/ar...d/Mbox-Drivers
All you can do is test if the latest driver works, (and you are approving any security permissions to let the driver install) and the device shows up in CoreAudio Audio/MIDI setup. If not, it's a door stop. I'd be very surprised if it worked.
The Mbox 3 family is so beyond end of life/so not cared about by Avid they don't even list it in the end of life table.
https://avid.secure.force.com/pkb/ar...-support-dates.
Avid ran fast from the consumer hardware market, which was finally the right thing for them to do. Unfortunately they should never have been trying to sell this stuff.
There are lots of great interfaces available from RME, UAD, Motu, Apogee, Focusrite, Presonus, ... if you explain your needs/interest folks here can suggest stuff for you. Otherwise I expect you'll need to roll back macOS versions.