With the new incrementInventory( ) API you can manually increment a product variant’s stock in the store’s inventory. Pass a variant ID and either a product ID or an inventory item ID, as well as the number to increment by.
Learn more: https://www.wix.com/velo/reference/wix-stores-backend/incrementinventory
See also: https://www.wix.com/velo/reference/wix-stores-backend/decrementinventory
