minecraft-expanded-datapack/assets/undeadm-m1/models/item/melee_weapon/diamond_great_axe.json

{
  "parent": "undeadm-m1:item/base_weapon_great_axe",
	"textures": {
		"layer0": "undeadm-m1:item/melee_weapon/diamond_great_axe"
	}
}