Thunder Client can be looked like an alternative to Postman.

Postman is a popular API client that makes it easy for developers to create, share, test and document APIs. This is done by allowing users to create and save simple and complex HTTP/s requests, as well as read their responses. 

Thunder Client is a GUI based Rest API Client Extension for Visual Studio Code, hand-crafted by Ranga Vadhineni with simple and clean design.

Thanks the extension, no need anymore to switch between differents platforms/windows , in order to test our API . We can make it in one place : direct in our VS Code.