minecraft-assets/data/minecraft/recipes/copper_ingot_from_smelting_raw_copper.json

{
  "type": "minecraft:smelting",
  "category": "misc",
  "cookingtime": 200,
  "experience": 0.7,
  "group": "copper_ingot",
  "ingredient": {
    "item": "minecraft:raw_copper"
  },
  "result": "minecraft:copper_ingot"
}