If you are using PrestaShops advanced stock management option, you can add your products to a warehouse by mapping your desired warehouse reference number to the warehouse.
Note: When importing a stock movement your Product must have a price as well as a quantity
You will also need to have a quantity (Quantities -> Quantity) value mapped as this is used for the physical quantity in the warehouse.
You can add your product to multiple warehouses by pressing the "More" button beside Warehouse and mapping additional warehouse references.
Importing a Stock Movement
To import a stock movement you need to map a quantity for the movement to the Quantity to Add field. Your product should have a unit price set as this is used in for the stock movement price. You can set the reason for stock movement in Step 2 by changing the Stock Movement Label setting.