outOfProcess.cs

public class OrdersController : Controller
{
    private readonly IAmACommandProcessor _commandProcessor;

    public OrdersController(IAmACommandProcessor commandProcessor)
    {
        _commandProcessor = commandProcessor;
    }

    [HttpPost("/sales/orders/{orderId:Guid}")]
    public IActionResult PlaceOrder([FromRoute]Guid orderId)
    {
        var request = new PlaceOrder
        {
            Id = Guid.NewGuid(),
            OrderId = orderId,
        };

        _commandProcessor.Post(request);

        return NoContent();
    }
}