Where do I find the PreShared Key? You can find your PreShared Key within the MMS. We have a full user guide available within our developer zone, and your PreShared Key can be found under Account Admin> Account Settings. Related articles Where do I get my Test gateway account details from, for testing the site? PreShared Key GDPR: How we use your personal data I am seeing the error message "Could not communicate with Payment Gateway" how can I fix this? Does the payment gateway return the customer back to the merchant's website after the transaction?