Most newer BMWs, and even a lot of older ones, as far back as the e90s at least didn’t come with spares. OEM tires are run-on-flat tires with stiffer sidewalls made to run up to 50 miles with 0psi at speeds up to 50mph. Some came with air compressors and fix-a-flat fluid(which doesn’t work, don’t use it, please, as a tire tech, I beg of you, it’s a mess) instead of a spare. As far as I know, just looking from looking at your car, they should be run on flat tires because tires in that size are almost always only run flat tires.

For future situations, even with run-on-flat tires, keep an air compressor in your car and learn what PSI your tires are supposed to run at. (Don’t read it off of the tire, read it from the door placard, on the tire has the max PSI the tire can handle only) If the pressure drops significantly, pull over, use the air compressor, air the tire up, and limp it to a shop. I personally don’t like run-on-flat tires on my cars, so I have regular tires on my e90, I just keep an air compressor in my car. If it drops on pressure, I add air, and limp it home.