Traktor is a paid 3rd party hardware and software that you can use to broadcast live. You can broadcast live with Traktor Pro 2 (or 3) by using the same settings that you would use for any other 3rd party live broadcast software, which you can find by clicking the "How do I connect?" link in the upper right of Airtime Pro.
You will need to make sure that your Master Username is "source" in order for Traktor to be able to connect. You can read more about how to connect your Traktor software in the Tracktor manual.