curl --request POST \
  --url https://api.zapier.com/v2/actions/{action_id}/outputs \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "data": {
    "authentication": "example_QVaAreV1",
    "inputs": {
      "someparam": "somevalue"
    }
  }
}'

{
  "data": [
    [
      {
        "id": "commit__message",
        "sample": "Git 2.0",
        "title": "Commit Message",
        "type": "output_field"
      }
    ],
    [
      {
        "id": "parents[]sha",
        "sample": "4a28f169ad29ba452e0e7bea2583914c10c58322",
        "title": "Parents Sha",
        "type": "output_field"
      }
    ],
    [
      {
        "id": "parents[]url",
        "sample": "https://github.com/git/git/commit/4a28f169ad29ba452e0e7bea2583914c10c58322",
        "title": "Parents Url",
        "type": "output_field"
      }
    ]
  ],
  "meta": {
    "count": 3,
    "limit": null,
    "offset": null
  },
  "links": {
    "next": null,
    "prev": null
  }
}