If you've enabled MusicKit in the Apple Developer Portal but your build fails with "Provisioning profile doesn't include the entitlement," here is the fix:
Do NOT add the entitlement to app.json.
Apple now treats MusicKit as a Runtime Service, meaning it is checked on Apple's servers when the app runs, not stamped into the .mobileprovision file at build time.
Topic:
Code Signing
SubTopic:
Entitlements
Tags: