OHLC API chart data for a cryptocurrency can be accessed by making a request to a specific endpoint that returns the data in a format that can be used to generate the chart. The endpoint may require certain parameters to be passed in the request, such as the cryptocurrency symbol, the time frame for the data, and the start and end date for the data.
For example, an API endpoint for Bitcoin OHLC data for a 1-day time frame could be accessed by making a GET request to the endpoint 'https://crypto-ohlc.p.rapidapi.com/api/v2/ohlc/btcusd' . The API would then return the data in a format such as JSON, which can be used to create the chart.