curl --request GET \
  --url https://macrobymark.com/api/indicators/discover \
  --header 'X-API-Key: <api-key>'

{
  "discoveryResults": [
    {
      "entry": {
        "provider": "<string>",
        "sourceSeriesKey": "<string>",
        "title": "<string>",
        "frequency": "<string>",
        "countryCode": "<string>",
        "countryName": "<string>"
      },
      "score": 123
    }
  ],
  "totalDiscoveryMatches": 123,
  "catalogs": {}
}