Post method returns 404 in Asp.net core Web API Controller

Routes code below:

app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",
                    template: "{controller=Home}/{action=Index}/{id?}");
            });

Controller code below :

// POST api/values
        [HttpPost]
        public void Post([FromBody]Employee employee)
        {
            employeeManager.CreateAsync(employee);
        }

All other methods working except the post method.

call from angular component :

 onSubmit(employeeItems: any) {        
        console.log(employeeItems);
        this.getData();
        var headers = new Headers();
        headers.append('Content-Type', 'application/json; charset=utf-8');
        this.http.post('api/Employee/Post', employeeItems, { headers: headers }).subscribe();
        this.createEmployeeFlag = false;
    }

I tried even from Postman, but no luck.