src/main/resources/assets/aether_legacy/recipes/skyroot_axe.json

{
  "type": "minecraft:crafting_shaped",
  "pattern": [
    "XX",
    "X#",
    " #"
  ],
  "key": {
    "#": {
      "item": "aether_legacy:skyroot_stick"
    },
    "X": {
      "item": "aether_legacy:skyroot_plank"
    }
  },
  "result": {
    "item": "aether_legacy:skyroot_axe"
  }
}