You can find this section in HostBill Admin → Settings → Apps Connections.
App Connection details lists:
In this section you also have the option to:
HostBill enables to add multiple connections to one module. To do so, use the 'Add new connection' button, enter the connection name and configure the connection as per module's requirements.
If you have multiple connections, the first one added is used as default, but it can be changed as requested by clicking on Change Default Server option.