How can I use AIR³ as a power bank?

You can even use AIR³ as a power supply to charge your phone.
For example, if your phone requires USB-C, use a USB-C to USB-C cable …. or use the small white USB-C/USB-A connector provided to use your regular USB-A to USB-C cable. Start AIR³, exit XCTrack if it starts automatically and turn off the screen with a short press on the power button.