Help with  SignerIdentityReportInfo parameter formatting C#

How to pass this parameter SignerIdentityReportInfo to Adobe API.

https://secure.na1.echosign.com/public/docs/restapi/v6#!/agreements/createSignerIdentityReport

example from Adobe page:

{
  "securityOption": {
    "openPassword": "MYPasswordHere!"
  }
}

    //I have tried to post like this. No luck for far. 

    string body= @"{ ""SignerIdentityReportInfo"":{ ""securityOption"":{ ""openPassword"":""MYPasswordHere!""} } } ";
    
    //or this 
    
     var body = JsonConvert.SerializeObject(new { securityOption = new {openPassword = "MYPasswordHere!" } });

    //or this 
    var body= @"{""securityOption"":{""openPassword"":""MYPasswordHere!""}}";

//used it like this.     request.Parameters.Add(new Parameter()
                {
    
                    Name = "SignerIdentityReportInfo", 
                    Value = body,
                    ContentType = "application/json",
                    Type = ParameterType.RequestBody
                });