Predicate parse error

I am having an error when using a predicate that was generated with the misode generator for 1.20.4.
This is the file:
[
  {
    "condition": "minecraft:entity_properties",
    "entity": "this",
    "predicate": {
      "equipment": {
        "mainhand": {
          "items": [
            "minecraft:bundle"
          ]
        }
      }
    }
  }
]

And this is the Error i am getting in the logs:
Couldn't parse element predicates:lootbundles:mainhand - Not a json array: {"condition":"minecraft:entity_properties","entity":"this","predicate":{"equipment":{"mainhand":{"items":"minecraft:bundle"}}}}

Can anyone spot what is wrong with this?