curl --request GET \
  --url https://prod.featherhq.com/api/v1/calendars/{calendarId}/connections \
  --header 'X-API-Key: <api-key>'

{
  "connections": [
    {
      "id": "<string>",
      "calendarId": "<string>",
      "accountEmail": "<string>",
      "externalCalendarId": "<string>",
      "invalid": true,
      "createdAt": "<string>",
      "updatedAt": "<string>"
    }
  ]
}