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".

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.