Storage partial update by REST API

How can I partial update a storage object by REST API?
for example update just save field:

        "collection": "saves",
        "key": "savegame",
        "value": "{\"save\":123,\"nosave\":456}"

@nkadd I wrote a large post on how best to do this at the moment with Nakama server:

In the future we plan to add JSON path support to perform partial updates as an official API in the storage engine.