You can check your Google Play Store order number on the payment receipt sent to your Google Account mailbox
or directly through Google Payments Center.
■ How to Check Your Order Number in Google Payments Center
1. Go to Google Payments Center (payments.google.com).
2. Log in with your Google account.
3. Go to Subscriptions and services > View purchase history > Select an order and check the transaction ID on your receipt.
* List an order number starting with GPA or attach a screenshot.