When using an unsigned IPA the IPA needs to be signed with your account. You can learn more about this here, in the section: Code Signing Identity.

Note: You must be using a Mac to successfully complete this process.

The steps to successfully complete the process are:

  1. Create a distribution certificate(p12 file) on the iOS developer portal. If you already have one, skip this step.
  2. Create an App ID on the iOS developer portal. This needs to be unique to the app (same as the Bundle ID that you selected on the submission).
  3. Create an App Store distribution provisioning profile on the developer portal, linked to the App ID and the Distribution Certificate created earlier.
  4. Install certificate (p12) and provisioning profile on your machine.
  5. Follow the steps here to re-sign the app, under the section: Signing Your Code Manually.

In order to publish on the App Store:

  1. Login to App Store Connect, create app associated with App ID from developer portal.
  2. Populate the app listing with all the correct data, screenshots etc
  3. Upload the IPA using to App Store Connect using Application Uploader
  4. Submit to store