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

{
  "type": "minecraft:smithing_trim",
  "addition": {
    "tag": "minecraft:trim_materials"
  },
  "base": {
    "tag": "minecraft:trimmable_armor"
  },
  "template": {
    "item": "minecraft:rib_armor_trim_smithing_template"
  }
}