“To enable credit card processing profiles for use in Release Preview:
1. In an Administrator role ,access your Release Preview account.
2. Go to Setup>Accounting>Financial Statements>Payment Processing Profiles.
3. Click Edit next to the credit card processing profile you want to use in Release Preview.
4. On the credit card processing profile, under Authentication Credentials, enter the credentials required for this processor.
5. Click Save.
6. Repeat these steps for each credit card processing profile you want to use in your Release
Preview account.” — crappy cut & paste, but you get the idea