The "Is Critical Jobstream" attribute is not available to be passed via the RestAPI subscription service.
Product: Automation Analytics & Intelligence 24.x
Product limitation
The enhancement will be included in the future release of AAI but there's no ETA yet.
DE168700: Restore "is Critical" functionality. The scope of the feature is not just limited to the REST API, but will include the ability to filter based on this flag throughout the UI.