In this step, you will verify whether the player has any purchases awaiting consumption. It is best to perform this check after the onInitialized trigger, as this allows you to validate the purchase and complete the process. You can also decide where and when to trigger this method based on your needs.. 
CheckoutController.GetNoneConsumedOrders(String customerId);
ArgumentDescription
customerIdRepresents the customer identification
This method returns an array of strings, with each string representing a different order ID. These IDs correspond to completed purchases that are awaiting consumption. You can then initiate a “Purchase Consume” for any order as needed.