Open the HVAC controls and press the button that corresponds to the dash vents. Then make sure the little knob/spinner on each vent isn't set to "closed"
I had the same problem when I took delivery of my 2021 MME. I called the dealer to set up a service appointment and they suggested I rotate the roller next to each of the dash vents since they are typically closed coming from the factory. I felt a little dumb but in my defense (and possibly in yours) the rollers aren't that easy to see.