The version is 24R2. Cloud. I’m studying the MroTechnicianTaskExecutionHandling.svc for some time and I have a hard time to collect data about specific Assignments using a generic integration user to authenticate with. 

Do you have any hints on calling this API to return data ? 

Running the URL in the browser with me logged in, gets several data sets, however with the service user, the result dataset is empty.

EDIT : Tried base_url]/MroTechnicianTaskExecutionHandling.svc/OngoingAssignmentsSet(TaskSeq={T'TASK_SEQ']},ExecutionInstanceSeq={a'EXECUTION_INSTANCE_SEQ']})

and the result is 

{'error': {'code': 'ODP_RESOURCE_NOTFOUND', 'message': 'Resource not found.'}}
.base_url]/MroTechnicianTaskExecutionHandling.svc/OngoingAssignmentsSet(TaskSeq=65,ExecutionInstanceSeq=1)