To define a product in ERPAG as 'dropshipped' means that the seller doesn't keep the product in this stock, but order it from a third party and sends it directly to the customer.
This does not affect the stock card.
To assign the dropshipping option to a product, go to
Inventory > Products & Services > open the wanted product
Once you've done that, in the fulfillment line you will be able to define the 'back order' field as 'dropshipping' by selecting it from the drop-down menu.
Now, when we crate a sales order with this particular product and save it, the 'dropshipping' button will appear.
The status of the document will change to 'ordered'.
This will automatically create a purchase order on the purchaser order list towards your supplier, for the wanted item.
Once the costumer receives the item, click on the 'receive' button in the created purchase order, so you will have the available quantity to pack and ship the sales order, in order to invoice it and issue that invoice to your customer.