minecraft-packets/minecraft-packets/data/pc/1.20.1/from-server/set_slot/2.json

An easy way to query PrismarineJS/minecraft-packets

{
  "windowId": 0,
  "stateId": 4,
  "slot": 36,
  "item": {
    "present": true,
    "itemId": 1055,
    "itemCount": 1
  }
}