_opendistro endpoint not available

General Feedback
1

Hi,
Im trying to use the _opendistro endpoint but I get an error:

GET _opendistro/_anomaly_detection/detectors/results/_search

{
  "error" : {
    "root_cause" : [
      {
        "type" : "parse_exception",
        "reason" : "request body or source parameter is required"
      }
    ],
    "type" : "parse_exception",
    "reason" : "request body or source parameter is required"
  },
  "status" : 400
}

Do I need to enable the endpoint before?

thanks
Martin