create-expandedcopper-compat/data/crafting/recipes/copper_chain_create.json

{
    "type": "minecraft:crafting_shaped",
    "pattern": [
        "N",
        "I",
        "N"
    ],
    "key": {
        "I": {
            "item": "minecraft:copper_ingot"
        },
        "N": {
            "item": "create:copper_nugget"
        }
    },
    "result": {
        "item": "extendedcopper:copper_chain",
        "count": 1
    }
}