set_creative_slot failure

[TheOfficialSeb]

[ ] The FAQ doesn't contain a resolution to my issue

Versions

• minecraft-protocol: 1.35.0
• server: vanilla 1.18.2
• node: v16.6.2

Detailed description of a problem

When sent the packet fails go through the minecraft server and give me. Seems like it's not correct.
[18:23:17] [Server thread/INFO]: AlphaServer lost connection: Internal Exception: io.netty.handler.codec.DecoderException: java.io.IOException: Packet 0/40 (wv) was larger than I expected, found 24 bytes extra whilst reading packet 40

Current code

var Item = {
    "present": true,
    "itemId": 847,
    "itemCount": 1,
    "nbtData": {
        "type": "compound",
        "name": "",
        "value": {
            "Decorations": {"value": {"type": "compound","value": []}},
            "map": {
                "type": "int",
                "value": 15
            }
        }
    }
}
client.write("set_creative_slot",{
    "slot": 45,
    "item": Item
})

Expected behavior

Should set slot 45 to a map