Guide

1. On Postman's main workspace, go to the left-side panel and click 'Collections'.

2. After that, select the collection where you wish to create documentation.

3. Tap 'View Complete Documentation' to proceed.

4. Next, click the entry box right below the title field and then write a detailed description. Make sure that it includes vital API information like authentication methods, parameters, request bodies, response bodies, headers, and examples.

5. Finalize the format of the description using the available options in the floating bar.

6. Once done, click anywhere outside the entry box to apply the changes.

7. Finally, the documentation will be created and added to the selected Postman collection.