Macbook airs have at least 1 USB port port, i don't believe apple made any airs that have no ports
Can you post pics of the sides of yours?
right in the description of the unit it says bluetooth is supported
https://www.pioneerdj.com/en/product/controller/ddj-flx4/black/overview/
Multi-device support
Whether you want to connect to a PC, Mac, iPhone, iPad, or an Android phone or tablet, the DDJ-FLX4 is versatile in its design. Even better, if you use the controller with rekordbox for iOS/Android, you'll be able to connect to your device via Bluetooth® or USB cable. So, there’s nothing to hold you back from giving DJing a try.