How to test post method in fiddler - web api

[miss786]

I am trying to test my post method using fiddler as below: In the [Composor] tab, I am calling the following url [http://localhost:45361/api/test\], in the [Parse] tab using method type as [POST]. In the [Request Header], I have [User-Agent: Fiddler, Content-Type: application/json; charset=utf-8] and in [Request Body], I am filtering: { "name":"storm" } However, the above post request, returns the entire dataset instead of records with name = storm. I have tried changing the method to [FromBody], which causes reference error in the code: Object reference not set to an instance of an object

[HttpPost]
public HttpResponseMessage post([FromBody] Query query)
{
IQueryable Data = null;

            if (!string.IsNullOrEmpty(query.tag))
            {
                var ids = query.tag.Split(',');
                var dataMatchingTags = db.data\_qy.Where(c => ids.Contains(c.TAG));

                if (Data == null)
                    Data = dataMatchingTags;
                else
                    Data = Data.Union(dataMatchingTags);
            }

            if (!string.IsNullOrEmpty(query.name))
            {
                var ids = query.name.Split(',');
                var dataMatchingTags = db.data\_qy.Where(c => ids.Any(id => c.Name.Contains(id)));

                if (Data == null)
                    Data = dataMatchingTags;
                else
                    Data = Data.Union(dataMatchingTags);
            }

            if (Data == null) // If no tags or name is being queried, apply filters to the whole set of products
                Data = db.data\_qy;

            if (query.endDate != null)
            {
                Data = Data.Where(c => c.UploadDate <= query.endDate);
            }

            if (query.startDate != null)
            {
                Data = Data.Where(c => c.UploadDate >= query.startDate);
            }

            var data = Data.ToList();

            if (!data.Any())
            {
                var message = string.Format("No data found");
                return Request.CreateErrorResponse(HttpStatusCode.NotFound, message);
            }

            return Request.CreateResponse(HttpStatusCode.OK, data);
        }

please advice, if I am missing something or my approach to te