So far, I've downloaded the SoupChef example and it works fine ... though it's a Catalyst app, so different than what I'm doing.
And now I tried to create an Intents Extension to try that out, and I can't get past provisioning profile issues. Even set to "automatic provisioning" (like the main app target is), it complains with this error:
Provisioning profile "Mac Team Provisioning Profile: com.test.MacSiriExtension" doesn't include the aps-environment and com.apple.developer.siri entitlements.
When I look in the Xcode target "Signing & Capabilities" tab, it doesn't really list any option for adding "Siri" like it does in the iOS app target. This is using Xcode 13.1, running on macOS Monterey RC. I've checked both the app target and the extension target.
I've also gone to the developer portal, and in the app's Identifier, manually added "SiriKit" to the target (though the popup says "Platform Support: tvOS, iOS, watchOS") and doesn't list macOS here.
Could it be that manually adding SiriKit to a Mac app isn't possible right now?