I wrote a detailed series of posts for Pluralsight which outline the exact process of how this is done. You can take a look at the tutorials over at Pluralsight - the third one (the fourth one is here). The section you'll be most likely interested in is titled How to test our application on the real physical devices and emulators).
If you're interested to learn a bit more about Ionic framework from start to publishing the app in the stores you can take a look at the ebook I made from 4 posts I wrote for Pluralsight (totaling over 20k+ words): https://leanpub.com/ionic-framework. You can get the book for free if you want, just enter 0 as amount.
The process is rather too long to explain in detail here, so I urge you to take a look at the links I provided. However, for reference steps you should take are:
- Get Apple developer license
- Install Xcode
- Create a build file with
ionic build ios
- Open up the generated project with Xcode
- Connect your phone (or use the simulator)
- Run your app on phone (or simulator)
Hope this helps.