With the free plan, you can simply start using the API right away - No API keys or account are needed.
API key is currently only available for CoinGecko API paid plan subscribers. Your Pro API Ket would only reveal once you have generated the API key in the Developers Dashboard. Do note that if the API key is compromised, you will need to delete this key and generate a new API key.
For more demanding applications looking to scale, you may consider our Enterprise plans. Do check it out here: https://gcko.io/enterpriseapi