During the sandbox payment test, the server performs the order token verification, and the verification fails with an error code of 8. Because the product is not owned, the consumption or confirmation fails.
May I ask whether the token verification cannot be performed under the sandbox payment test?
Generally erroCode:8 returns due to a user failed to consume or confirm a product because the user does not own the product.
Please check that product is already purchased , if it is already purchased, please check and consume product by calling the consumeOwnedPurchase API to consume the product and send a notification to the Huawei IAP server to update the delivery status ,purchaseToken is passed in the API call request. After the consumption is complete, the Huawei IAP server resets the product status to available for purchase. Then the product can be purchased again.
For more details , please refer the below link: https://developer.huawei.com/consumer/en/doc/development/HMSCore-References-V5/api-purchase-confirm-for-order-service-0000001051066054-V5