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

{
  "type": "minecraft:crafting_shapeless",
  "category": "redstone",
  "ingredients": [
    {
      "item": "minecraft:polished_blackstone"
    }
  ],
  "result": {
    "item": "minecraft:polished_blackstone_button"
  }
}