Candlestick chart represents the fluctuation of prices in a time frame. From the data passed to the candle function as an argument, the candlesticks are plotted which shows the opening and closing prices in the time frame ie, the fluctuation occured in the prices in each time frame. Markers on the other hand are specific data points which occur in the dataset and in the case of candlesticks chart would not be the correct way to visualise data.
However to see the opening and closing values of a candlestick, you can click on the opening and closing price on the candles in the generated candlestick chart.
Please refer to the below documentation on candlestick graph for more information: