First, download the free version of Postman from https://www.postman.com/downloads/
It's available for all three major platforms: Linux, macOS, and Windows. Alternatively, there is also a web version of Postman.
Before getting started with Postman, you need to create an API key and secret via the fiskaly dashboard.
Next, go to the API v2 Quick Start page and enter your API key and secret in order to obtain your personalized Postman environment:
Now you are ready to begin using Postman.