Notional Orders - C# Nuget

I’m trying to place a notional (dollar value) TimeInForce.Day order for SPY.

Here is my code :

            OrderQuantity orderQuantity = OrderQuantity.Notional(100.00M);

            NewOrderRequest orderRequest = new NewOrderRequest(ticker, orderQuantity, OrderSide.Buy, OrderType.Limit, TimeInForce.Day);
            orderRequest.ClientOrderId = "Test";
            orderRequest.LimitPrice = 700.00M;
            IOrder order = Client.**PostOrderAsync**(orderRequest).Result;

However I get this exception message when PostOrderAsync is called.
—> Alpaca.Markets.RestClientErrorException: qty is required

I got this response in the community Slack.

“You can’t specify a limit order there. Fractional orders are market orders only right now”