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

The volume chart indicator reflects the number of shares or contracts bought and sold within a specific timeframe. However, direct trading is not possible when it comes to indices like Nifty or other similar ones. Instead, trading on indices is conducted through derivatives, i.e. F&O contracts or ETFs. As indices do not have actual trades taking place, there is no available volume data. Consequently, it is not possible to add volume-based indicators to the charts for indices due to the absence of trading activity.