Tells the delegate that the request failed to execute.
- iOS 3.0+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.2+Beta
The request that failed.
The error that caused the request to fail.
When the request fails, your application should release the request. The
request method is not called after this method is called.