There is a new OpenAPI 3 schema available as of March 2026. See this post for details:
Feature Request : OpenAPI for REST API - #17 by Amm0
But for Postman, the RAML scheme is still recommended since it always load. The OpenAPI 3 format some times fails to load. I think there is a timeout. RAML takes several minutes and looks hung for 1-2 minutes of that after import. Once imported, it's fine.
Feel free to try the OpenAPI 3 in Postman... I've seen OpenAPI 3 load, but actually seems even slower to load than RAML when it does. YMMV.
NEW Web-based REST API Schema Viewer
The link above has more details. But you can use that instead of load Postman if need is just to lookup a curl command for REST API...
