Before your changes go to
Live website i.e. on the Production mode, to discover problems and fix them right away you can set up the Preview Servers and review the content changes instantly.
You can look at the default Preview Servers under Manage Project :
The default servers are
Production and are setup to a sample URL which can be modified with your website URL or some API or an Application.
To add your Custom Server, you can click on
Add Preview Server and set-up the server as you intend to as follows:
You can choose your custom Preview Server as a Preview Endpoint for the Lifecycle States. To do that you can Go to Lifecycle States, under Manage Project Publishing Settings.