Purchase Order
You can receive stock from a Purchase Order also. In this case you should first create a Purchase Order, and send it to the supplier. Once you have received goods for the Purchase Order you can receive goods by creating a Purchase Receive.
First go to Inventory > Purchases and click "+ New" to create a new Purchase Order.
Once you've created a Purchase Order add products to the PO.
After you've added products to the PO, you can Approve the Purchase Order to finalize it by clicking the "Approve" button at the top.
After a PO is approved, you can receive goods by clicking the "Receive Items" button on the PO details page. Once you enter the quantities and receive items the inventory will be added to the system for the product.