Unable to pass json object in web api

namespace DemoApi.Controllers
{
    public class EmployeeController : ApiController
    {       
        IList employees = new List() 
        {
           new Employee()  
                {  
                    EmployeeId = 1, EmployeeName = "Mukesh Kumar", Address = "New Delhi", Department = "IT"  
                },  
                new Employee()  
                {  
                    EmployeeId = 2, EmployeeName = "Banky Chamber", Address = "London", Department = "HR"  
                },  
                new Employee()  
                {  
                    EmployeeId = 3, EmployeeName = "Rahul Rathor", Address = "Laxmi Nagar", Department = "IT"  
                },  
                new Employee()  
                {  
                    EmployeeId = 4, EmployeeName = "YaduVeer Singh", Address = "Goa", Department = "Sales"  
                },  
                new Employee()  
                {  
                    EmployeeId = 5, EmployeeName = "Manish Sharma", Address = "New Delhi", Department = "HR"  
                },  
        };

        public IList GetAllEmployees()
        {
            //Return list of all employees  
            return employees;
        }       

        [HttpPost]       
        public Employee GetData([FromBody] int id)
        {
            var employee = employees.FirstOrDefault(e => e.EmployeeId == id);

            if (employee == null)
            {
                throw new HttpResponseException(Request.CreateResponse(HttpStatusCode.NotFound));
            }
            return employee;
        }

    }
}