I would like to know how to enter individual parts per vendor invoice as I did in Quickbooks Desktop. Does anyone know how do this?

COGS is only for items cost that are stocked as inventory items

but be sure you have track items turned on in company settings, then on the purchase click the items detail at the bottom and enter the items one at a time

@Ph1709 

When you purchase inventory, you post it to your inventory asset account, not COGS.  When inventory sells, it is then posted to COGS, hence the name cost of goods "sold".

Inventory is not an expense until sold, if it was, it would be easy for a company to manipulate its income by purchasing a bunch of inventory at year-end, thereby reducing its income and reducing its tax liability.  The IRS is not fond of that sort of thing which is why companies that keep inventory generally must use the accrual method of accounting.