In addition to being done in the Working Order, Sizing and Delivery can be added directly from the Product Details pane.
To add a product to your Working Order with Sizing, just enter the desired quantities directly in the available fields in the Product Details pane.
To Add a Product to your Working Order with Delivery, then we would recommend adding units in the correct delivery window date.
Once you've entered your desired Sizing and Dates, just click the ADD TO ORDER button to add the product to your Working Order with your quantities and deliveries.
You may also reference this help article link below to review further on the different delivery window options: