Integration Broker - Query Parameters missing

WE are attempting to execute a generic URL connection with an external vendor(va HTTPS) and we are getting a message saying the query parameters are not valid on the URL string. We used the AddConnectorProperties using both %HTTPHeader and %HTTTProperty with no success.  We have tried using the AddQueryStringArg method as well but we are receiving the same error.

In reviewing a number of PeopleSoft documents, we found code that will pass the Query values into the URL request using the SetContentString method. The format of the code is -

&MSG1.SegmentContentType = "application/x-www-form-urlencoded";

&bRet = &MSG1.SetContentString("grant_type=authorization_code");