If your transaction fails due to the "TokenExt" parameter, it may be due to various reasons. In this case, please check the following points:
- The most common reason is a malformed JSON object passed as "TokenExt". In our documentation you can find an example of a correct object: https://developer.computop.com/display/DE/Google+Pay
- Have you submitted the transaction in the correct system (Test- or live system) and has your Google Pay implementation been approved by Google? Here you can find more information: https://developers.google.com/pay/api/web/guides/test-and-deploy/deploy-production-environment
If the transactions still fail with the above error, please contact us. We will be happy to check if your MerchantID is configured for the correct environment (live or test).