You can import your existing OpenAPI 3.0 and 3.1 definitions (OpenAPI Specification) into Postman. Postman supports both YAML and JSON formats. Spec Hub supports OpenAPI 2.0, 3.0, and 3.1.
To import an API definition into Postman, click 
Options in the sidebar and select Import. You can choose to upload a file or folder, enter a URL, paste your raw JSON or YAML, or import from a code repository. Learn more about how to import an API into Spec Hub.
After importing your API into Spec Hub, you can edit your API specification, view and fix syntax errors in your specification, or generate a collection.