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

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "###",
    "#X#",
    "###"
  ],
  "key": {
    "#": {
      "item": "minecraft:nautilus_shell"
    },
    "X": {
      "item": "minecraft:heart_of_the_sea"
    }
  },
  "result": {
    "item": "minecraft:conduit"
  }
}