{
  "type": "sophisticatedbackpacks:backpack_upgrade",
  "conditions": [
    {
      "type": "sophisticatedcore:item_enabled",
      "itemRegistryName": "sophisticatedbackpacks:iron_backpack"
    }
  ],
  "key": {
    "B": {
      "item": "sophisticatedbackpacks:backpack"
    },
    "I": {
      "tag": "forge:ingots/iron"
    },
    "H": {
      "item": "minecraft:bundle"
    }
  },
  "pattern": [
    "IHI",
    "IBI",
    "III"
  ],
  "result": {
    "item": "sophisticatedbackpacks:iron_backpack"
  }
}