I am creating a simple POST API for an ASP.NET Core MVC + Razor app, which currently does not do much except returning a view:

```
public class CartController : Controller
{
    public IActionResult Add()
    {
        return this.View();
    }

    [HttpPost("Add"), ActionName("Add")]
    public IActionResult PostAdd() 
    {
        return this.View();
    }
}

```

It is registered like this in `Startup.cs`:

```
public void ConfigureServices(IServiceCollection services)
{
    services.AddRazorPages();
    services.AddControllers();
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
    //...
    app.UseRouting();
    app.UseEndpoints(builder => {
            builder.MapRazorPages();
            builder.MapControllers();
    });
}

```

When trying to GET /Cart/Add, everything works fine and the Add.cshtml view is returned. However, a POST request fails, returning a "400 Bad request" HTTP status code:

```
$.ajax( {
  method:"GET",
    success: console.log,
    url: "/Cart/Add"}) // works, HTML is logged to the console

$.ajax( {
  method:"POST",
    success: console.log,
    url: "/Cart/Add"})  //Fails: XHR POST http://localhost:5265/Cart/Add [HTTP/1.1 400 Bad Request 0ms]

```

Is there something obvious i am missing here? I believe it is probably a configuration issue, however i could not find any answers neither on stackoverflow nor elsewhere (in almost all other questions about this topic, the issue was caused by parameters passed to the controller or other attributes, which could hardly be the cause here, like [this one](https://stackoverflow.com/questions/69457998/bad-request-when-trying-post-in-asp-net))