curl --request GET \
  --url https://gateway.polymarket.us/v2/leagues

{
  "leagues": [
    {
      "name": "<string>",
      "slug": "<string>",
      "image": "<string>",
      "isOperational": true,
      "id": 123,
      "sportId": 123,
      "tagId": 123,
      "resolution": "<string>",
      "ordering": "<string>",
      "activeSeriesId": 123,
      "createdAt": "<string>",
      "abbreviation": "<string>"
    }
  ]
}