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

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    " #X",
    "# X",
    " #X"
  ],
  "key": {
    "#": {
      "item": "minecraft:stick"
    },
    "X": {
      "item": "minecraft:string"
    }
  },
  "result": {
    "item": "minecraft:bow"
  }
}