How do I run a test scenario in the sandbox environment for a FFF/XML API?
To run a sample transaction in the Sandbox, click the Run in Postman tab. A collection called "sandbox STS" opens and includes one request. Add in your credentials by navigating back to your app on your Dashboard and copy/paste your client ID into the username field and your client secret into the password field. When the authorization header is populated, click Send. A sample report opens.