curl --request GET \
     --url {{BASE_URL}}/v2/timeseries/{user_id}/blood_oxygen/grouped?start_date={{START_DATE}}&end_date={{END_DATE}} \
     --header 'Accept: application/json' \
     --header 'x-vital-api-key: <API_KEY>'

{
  "groups": {
    "oura": [
      {
        "data": [
          {
            "timestamp": "2023-02-13T14:30:52+00:00",
            "unit": "%",
            "value": 98
          }
        ],
        "source": {
          "provider": "oura",
          "type": "ring"
        }
      }
    ]
  }
}