For the items you purchased through the system, their quantity will be recorded automatically and displaying here.

Also, for the quantity you sold to your buyers, it will be deducted from the total stock amount. You can check your inventory balance anytime.

For the buyers who are authorized to see your inventory ( Under Data Management > Category setting > Attribute setting ), you might want to manually adjust the inventory level or stock amount to meet their expectation.

To build up inventory: