curl --request GET \
  --url https://api.stackone.com/unified/ats/application_stages \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'x-account-id: <x-account-id>'

{
  "next_page": "<string>",
  "next": "<string>",
  "data": [
    {
      "id": "8187e5da-dc77-475e-9949-af0f1fa4e4e3",
      "remote_id": "8187e5da-dc77-475e-9949-af0f1fa4e4e3",
      "unified_custom_fields": {
        "my_project_custom_field_1": "REF-1236",
        "my_project_custom_field_2": "some other value"
      },
      "name": "<string>",
      "order": 123,
      "created_at": "2021-01-01T01:01:01.000Z",
      "updated_at": "2021-01-01T01:01:01.000Z"
    }
  ],
  "raw": [
    {
      "method": "<string>",
      "url": "<string>",
      "body": "<string>",
      "response": {}
    }
  ]
}