Query JSON Cloud Save Player Data

Unity Services
,
1

Hi,

Is there a way to query cloud save that is JSON? Let’s say each player has the same key “STAT” that saves statistics of a player.

{
    "mapScore": {
        "MAP_01": 199,
        "MAP_02": 0
    },
    "fightCount": 0,
    "winCount": 0,
}

How do I set up index to let’s say fightCount where I query with API

{
    "fields": [
        {
            "key": "STAT",
            "value": null,
            "op": "NE",
            "asc": true
        }
    ],
    "returnKeys": [
        "STAT"
    ],
    "offset": 0,
    "limit": 100,
    "sampleSize": 100
}

I tried the query above but this has response

{
    "results": []
}

if I want to get for example fightCount within “STAT” > 0, how do I set it up?

Thanks in advance.