Why is the volume chart indicator not working for Nifty or other indices?

The volume chart indicator is designed to show the number of shares or contracts traded within a specific timeframe. However, when it comes to indices like Nifty or others, direct trading doesn’t occur. Instead, trading on indices happens through derivatives such as F&O contracts or ETFs. Since indices don’t involve actual trades, there is no available volume data. As a result, adding volume-based indicators to charts for indices isn’t possible due to the absence of trading activity.