Calling all musician and ProTools experts!

Hello Creators,
this is not my area, as I’m a graphic artist and illustrator, but my boyfriend is a musician and needs some help.
He bought a Mbox2 sound card months ago but can’t find the command to connect it to ProTools. The software simply doesn’t “see” it. He tried to look for YouTube tutorials and the user manual, but couldn’t find the solution
Have you had to deal with the same issue? How did you fix it?
Thank you all for your help! :slight_smile: