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

{
  "type": "minecraft:crafting_shapeless",
  "group": "copper_ingot",
  "ingredients": [
    {
      "item": "minecraft:copper_block"
    }
  ],
  "result": {
    "item": "minecraft:copper_ingot",
    "count": 4
  }
}