recipe not working

i made the recipe in the crafting table and the book simply doesn't appear
{
    "type": "minecraft:crafting_shaped",
    "pattern": [
        "  I",
        "ACI",
        "IO "
    ],
    "key": {
        "I": {
            "item": "minecraft:bone"
        },
        "O": {
            "item": "minecraft:beef"
        },
        "A": {
            "item": "minecraft:mutton"
        },
        "C": {
            "item": "minecraft:glistering_melon_slice"
        }
    },
    "result": {
        "item": "minecraft:knowledge_book"
    }
}