The documentation now states which addresses each account uses, and the Environment switch in the API Reference sidebar shows every example with the Demo addresses.

Deepinfo runs a Production and a Demo environment, and every account belongs to one of them:

• Production, for paid customer accounts: the platform at platform.deepinfo.com and the API at api.deepinfo.com/v1.
• Demo, for demo accounts: the platform at platform.deepinfodemo.com and the API at api.deepinfodemo.com/v1.

The examples on this site use the Production addresses. With a demo account, choose Demo in the Environment switch at the top of the API Reference sidebar: code examples and platform links then show the Demo addresses, and Copy copies them as shown. Your choice is remembered in this browser.

The details, including the Postman variables, are on Environments & base URL.