1. Development certificate
Click Certificates on the left. If you see the message:
If you do not have the WWDR intermediate certificate installed, click here to download now.
...then click the link to download the certificate. Once downloaded, double-click the file to add it to Keychain access.
We'll be requesting a Development certificate first. This is just for testing - for publishing the app, we'll need a Distribution certificate.
Click Request Certificate in the Development tab to request a development certificate. Follow the instructions to create and upload a Certificate Signing Request (CSR). Once you're done, you should see a Download button next to your certificate. If it says Pending, wait a moment and refresh the page, and it should appear. Once downloaded, double-click the file to add it to Keychain Access.
2. Registered device
Click Devices on the left. Here we can add a specific device for testing on.
You can actually add as many devices as you like, but let's just do one for now. Click Add devices. The Device Name can be any descriptive name you like. To get the Device ID, plug in your device with the USB cable and open iTunes. The device should appear under Devices in iTunes. Select it and you should be able to see the serial number in the Summary page. Click on the serial number and it should change to display the Identifier (UDID). That is the ID you need to use. You can copy and paste it to the Add Devices page. Click Submit and your device should be added.
3. App ID
You'll need an app ID for each app you want to publish. Click New App ID. Enter a descriptive name, which can be anything you like.
For Bundle Identifier, you need to enter a dot-separated list of words in the format com.companyname.appname, e.g. com.scirra.spaceblaster. If you reverse the words, it looks a bit like a .com web address. Remember this ID - you'll need to enter it when exporting to PhoneGap from Construct 2.
Click Submit and your App ID should be added.
Get your mobileprovision file
Click Provisioning on the left. Click New Profile. Now you can enter a descriptive name, and pick your certificate, app ID and device. Click Submit.
Like before, you might need to wait a moment, then a Download button should appear. Click it to download your .mobileprovision file. Remember where you put it, we'll need it in a moment again!