The KeyPay base connection is configured through the KeyPay API which you can find details about here - https://api.keypay.com.au/australia/reference
In Salesforce we hold the credentials that are required to connect to KeyPay through the KeyPay API in a Custom Setting which can be access via the Setup Menu.
Salesforce sandboxes are connected to the Key Pay Staging Environment for testing.
There are a set of Apex Classes developed to establish the base connection and to manage the different data services that are supported between the two systems.
