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

{
    "type": "minecraft:crafting_shapeless",
    "ingredients": [
        {
            "item": "create:copper_nugget"
        }
    ],
    "result": {
        "item": "extendedcopper:copper_button",
        "count": 1
    }
}