how to get the history data by using the free api

## Description
hi guys, i just apply the free api from the electric map website, but I find I can't use this API to get the historical data, how can l get the historical carbon intensity data?
I try to use this command but meet some wrongs.
curl 'https://api.electricitymap.org/v3/carbon-intensity/past?zone=DE&datetime=2025-01-19T00:00:00Z' \
>   -H 'my_api_key'
{"error":"Invalid auth-token"}