How can I plot the 15 min moving average on 5 min chart? I try to plot but the " based on" is always on Main Price Graph.
Thank you.

You need to change the Chart Region. If you want to plot the MA underneath the main chart, set the chart region to 2. The default region of 1 is the main chart itself.

I reached the goal. I needed to add an indicator called "Study/Price Overlay".
https://www.sierrachart.com/index.php?page=doc/StudyPriceOverlayStudy.php