I'm really struggling with making a basic post request in a url to support a tutorial on web api.

I want to do something like this in browser: <http://localhost:59445/api/group/post/?newvalue=test> and get the post to register. However I don't seem to be able to form the request correctly. What is the correct way to do this?

The error I receive is:

> 
> {"Message":"The request is invalid.","MessageDetail":"The parameters dictionary contains a null entry for parameter 'id' of non-nullable type 'System.Int32' for method 'System.String Get(Int32)' in 'twin\_groupapi.Controllers.GroupController'. An optional parameter must be a reference type, a nullable type, or be declared as an optional parameter."}
> 
> 
> 

my model:

```
    public class Group  
    {
     public Int32 GroupID { get; set; }
     public Int32 SchoolID { get; set; }
     public string GroupName { get; set; }
    }

```

routing:

```
public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services

        GlobalConfiguration.Configuration.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
        // Web API routes
        config.MapHttpAttributeRoutes();

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{action}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );
    }

```

controller:

```
    //[Route("api/Group/Post")]
    [HttpPost]
    public void Post([FromUri] string NewValue)
    {

        string newstring = NewValue;

    }

```