Import OpenAPI definition via url

Hi, I would like to know how to import an OpenAPI definition and an environment file directly to Postman web.

I have seen on some webpages that in order to import an API to Postman web they use a url with query parameters, such as{JSON OpenAPI definition url}?sv={date in format YYYY-MM-DD}&sr=b&sig={some kind of signature}&se={current date}&sp=r&configurable (see image attached to this description).

I tried to look it up in the Postman documentation, but I couldn’t find any indication of how this url should be created. What should be the value of the ‘sig’ parameter?

What I am looking for is exactly this functionality of importing the definition to the web, without having to use the Postman API.

Is there a way of passing to this endpoint the environment file?