Hi,
You can find the generalization and need to select the “Workflow” entity, as per the given below image.
Ref link: https://docs.mendix.com/refguide/entities
https://docs.mendix.com/refguide/workflows
https://medium.com/mendix/mendix-workflow-an-overview-a97aadf7cbc1
AND It is mentioned in the release notes that this is not necessary anymore as the workflow was beta previously:
Here you can find some docs on how to migrate from the beta workflow.
https://docs.mendix.com/refguide/workflow-beta-migration