How to add a request body to an IBM BPM 8.6 script task BPMRESTRequest object in order to invoke a REST api?

Question

I am trying to invoke a REST api (POST operation) from IBM BPM 8.6, I have to use a script task, I am able to call the api no problem just that the api expects a request body with a json object in it and I have not found a way yet to add that to the request object which I create in the script. I am able to add headers and parameters but not a http body to the request.

This is my code in the script tab of the the script task, the call is received by the api but it discards it with the message that the request is missing a request body which the api expects.

var request = new BPMRESTRequest();
request.externalServiceName = "api-docs";
request.operationName="extractReporterInfoUsingPOST";
request.httpHeaders =  {"Content-Type": "application/json", "Accept":
"application/json"};
request.httpMethod = "POST";
// request.body = {"test":"dummy"}; <- does not work
// request.httpBody = {"test":"dummy"}; <- does not work
var response = tw.system.invokeREST(request);

Answer 1

I had the same problem. I was able to solve this issue by specifying the post body like so:

request.parameters = { "body": { "key1": "val1", "key2", "val2" }}