This tutorial is about using Stratos Tokens App, but under the hood it’s using the Tropos engine (which is powering this api). The concepts described in this tutorial still apply to this api (such as structuring of your design document, produced output json structure and use of said structure).

The json structure shown in the screenshots of this article is what you get as response data when calling the Design Tokens extractor for Figma api.

https://medium.com/sketch2react/styling-react-components-using-stratos-design-tokens-dfe0e4e10247