In my case the issue was that I had 2 protocols, one extending another (I forgot what the Swift-appropriate term is), and I had two properties with similar name, but slightly different declaration. Like: protocol A { var field: { get throws } } protocol B: A { var field: { get } } And the build just died (same symptoms: hangs forever, nothing helps). Once I removed one of the two properties, the problem went away.

Like others have said above, looks like this tab has been renamed to "Integrations". And under "Integrations" if you are an Admin, on the left you will see "Keys" -> "App Store Connect API".