CPQ Document Api Missing Operations

I am trying to use the api related to CPQ documents as described here:

I need a way to retrieve quotes that relate to a specific deal. I can see that the UX is using such a call, but there doesn’t appear to be an official api version of this endpoint.

Here is the call the I can see the ux is making:


Where is the equivalent api (/crm/sales/api) that would return a list of documents or document ids that I could then use to retrieve the document from /api/cpq/cpq_documents/99999

Also is there an equivalent api call to retrieve a pdf version of the document? Again I can see the call the UX is making but this is not via the /api/ route but is /crm/sales/cpq/cpq_documents/31000051776/pdf

Thanks for the help