I'm new to Nintex and have been trying to find an API to get, schedule, start and stop workflows from a 3rd party application(Using postman for testing it for now). I have found this endpoint "http://<site>/_vti_bin/NintexWorkflow/Workflow.asmx" which provides administrative functionalities, but when I send a POST request to it and include an "op" parameter such as "op=StartWorkflow" , I keep getting the "soap:ReceiverServer was unable to process request. ---> Value does not fall within the expected range." message. I did some research on that and none of the solutions have worked. I do not know if endpoint is the correct way to go. I would really appreciate any help!