curl --request GET \
  --url https://gateway.polymarket.us/v1/series

{
  "series": [
    {
      "id": "<string>",
      "slug": "<string>",
      "title": "<string>",
      "subtitle": "<string>",
      "recurrence": "<string>",
      "image": "<string>",
      "active": true,
      "createdAt": "<string>",
      "updatedAt": "<string>"
    }
  ]
}