Convert Step Function Json to Definition object using Activity

I am new to CDK L2 construct. I am trying to create L2 construct for one of my step function definition. Currently it is in JSON Format want to make it to code. I tried using stepFunction.Activity but it is not taking Resource i.e. arn, Comment, Retry and catch attributes. Can someone help me out on functions usage. Read through the documentation but could not get the right function.

JSON :

{"Comment": "random-user-to-role-workflow","StartAt": "Notification Fail","States": {"Notification Fail": {"Next": "Failure","Resource": "arn:aws:states:us-india-1:8898762019:activity:Notification","Comment": "Failure Notification","Retry": [                {"ErrorEquals": ["States.ALL"                    ],"MaxAttempts": 3,"BackoffRate": 2                }            ],"Catch": [                {"ResultPath": "$.error","Next": "Failure","ErrorEquals": ["States.ALL"                    ]                }            ],"Type": "Task"        },"Success": {"Type": "Succeed"        },"Failure": {"Type": "Fail"        }    }}