Store › Inventory lists every item whose stock is tracked: on hand, held for checkout, available, units on order, average cost and stock value. Filter it to Low stock or Out of stock, search it, and export it as CSV.
Set a Reorder point on an item, on Inventory or on its product's Stock page. When its available stock falls to that point, the team's admins and owner get an email and a phone notification, once until it is restocked above the point. Low-stock alerts in Store settings turns the alerts off.