Subtracts a set number of items from inventory.
The decrementInventory() function returns a Promise that is resolved when the specified item's quantity has been updated in the inventory.
This method may require higher-level permissions than the caller has, based on their identity and roles and permissions. In these cases, you can ensure the method is called with the required level of authorization by using one of the following:
Item or product to decrement.
This method doesn't return any custom errors, but may return standard errors. Learn more about standard Wix errors.