Webhook Body capabilities to update a specific Child record in Firebase

If I have a Firebase child record with a KEY

jsontree_key

Is it possible for 2 Webhook Integrations to GET this one record and PUT back updates to this one record… I don’t want to POST… I want to just update this 1 key child record because my understanding is that my Xamarin Client app needs a KEY in Firebase to support TwoWay Binding, which I need for my app since the Client makes changes and my Particle Photon controller makes changes to this Firebase instance. Any help in understanding what is possible in Webhooks would be appreciated. Thank you, Brian

here’s my draft Webhook GET (I’m not sure how to go GET this specific Key as I may not know the Key value… I just want to GET the first record in the Child, which should be the only one… do I add a statement to my “query” section below like: “_Key”: “-M5sN1MfCHcXHkLBlwWW” or perhaps a “where” clause?

{
    "event": "ParametersRead",
    "url": "https://someDBhere.firebaseio.com/ControllerData/{{n}}/Parameters.json",
    "requestType": "GET",
    "noDefaults": true,
    "rejectUnauthorized": false,
    "query": {
        "auth": "myauthkeyblahblaheLgDDDWUbt3oVnfbB"
    }
}

Here’s my draft PUT (How do I PUT it back to update the same _Key record)

{
    "event": "ParametersWrite",
    "url": "https://someDBhere.firebaseio.com/ControllerData/{{n}}/Parameters.json",
    "requestType": "PUT",
    "noDefaults": true,
    "rejectUnauthorized": false,
    "query": {
        "auth": "myauthkeyblahblaeLgDDDWUbt3oVnfbB"
    },
    "body": "{\"Cyc\":{{Cyc}},\"LRPgm\":{{LRPgm}},\"LRWeb\":{{LRWeb}},\"LW\":{{LW}},\"PB\":{{PB}},\"PMode\":{{PMode}},\"PTog\":{{PTog}},\"Td\":{{Td}},\"Ti\":{{Ti}},\"fan\":{{fan}},\"ign\":{{ign}},\"aug\":{{aug}},\"pgm\":{{pgm}},\"mode\":\"{{mode}}\",\"target\":{{target}},\"u\":{{u}} }"
}