Before you can test your app on your iOS device, you first have to register it with your developer account. You can do this via Xcode or manually. We will show you the manual method.
Go to Apple Developer portal: https://developer.apple.com/account/
Start by selecting the "Devices" tab:
1) Press (+) to add your device
2) Give your device a name and enter its unique ID. The easiest way to find the uniqueID is to connect your iOS to your computer, open Xcode, Navigate to "Window-->Devices" and then select your device from the "Devices" tab. The device id is shown in the "Identifier" entry. You may need to expand the Xcode window to see all of the uuid, its long and could be cut off.
3) Press Continue
4) Press Register.