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

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