@eshan_23,
Tooltip will be shown only when you move mouse over the line & the data points and will not be shown for the filled region as of now.
If you are facing some other issue, kindly create JSFiddle reproducing the issue you are facing and share it with us so that we can look into the chart-options being used, understand the scenario and help you with a better solution.
—
Adithya Menon
Team CanvasJS