How can I connect my numark mix track pro 2 to my iPad I bought the hub and the camera adapter and connected it but still dose not work

First make sure iOS gets the midi signal. To do that, you can use a 3rd party application. Just search for midi viewer or so on the App Store.

When you press buttons or move faders you should get a lots of output in the application.

If that does work you might need to provide a Mapping file for day. Since the controller isn’t supported by DJAY on iOS out of the box.
If you have djay for OS X you can find the midi mappings in the Application bundle. Otherwise just search the web. I think you’ll find one.

If you do have the Mapping file you can transfer it to your iPad via iTunes.

Now you can use your controller with our iPad.
This process worked for me (with a Hercules DJ control Air)

Make sure you have put the mapping file in iTunes in the Djay folder.