Item Modifier “Set Damage” 1.21 enchanted chance

How would I achieve this in Minecraft?  I have the following, but it always ignores the enchanted chance for some reason:
{
  "function": "minecraft:set_count",
  "count": 0,
  "add": true,
  "conditions": [
    {
      "condition": "minecraft:random_chance_with_enchanted_bonus",
      "enchantment": "minecraft:unbreaking",
      "unenchanted_chance": 1,
      "enchanted_chance": {
        "type": "minecraft:fraction",
        "numerator": 1,
        "denominator": {
          "type": "minecraft:linear",
          "base": 2,
          "per_level_above_first": 1
        }
      }
    }
  ]
}