coin_id: CoinGecko coin ID (e.g. bitcoin). Can be retrieved from the '/coins/list' endpoint.
vs_currency: The target currency of market data (e.g. usd, eur, jpy, etc.)
days: The number of days of data for market chart. Allowed values are "1", "7", "14", "30", "90", "180", "365", "max". Make sure you include the double quotes.