https://sandbox.datadeck.co (use a Sandbox secret)
https://live.datadeck.co (use a Development or Production secret)

Deck has two environments: Sandbox and Live. Connections, once created, cannot be moved to another environment. The Sandbox environment supports only test connections. The Live environment supports real connections and can be used with a Development or Production secret. All testing should be done with Sandbox and Development secrets. All activity in the Live environment will be billed. When you’re getting ready to call the Live environment, request access via the Dashboard.