An indicator is a function built on the basis of trading statistics (such as opening and closing prices, minimum and maximum prices, trading volumes, etc.), the analysis of changes in the values of which allows predicting the future movement of the market. The values of the indicator functions can be displayed on the chart in the form of lines, columns, points, geometric figures, etc.
To see the available indicators, click on the Indicators button on the top panel of the chart, a window will open:
In the left part of the indicators window, you can select the category of indicators you are interested in: Built-ins, Public Library, My scripts, Volume Profile.
Just select the indicator you are interested in on the right side of the window and click on it - the indicator will appear on the chart, and its name, parameters and values will be displayed in the chart legend.