How to fill in the Select input box in the Metrics tab

Hi all,

I am trying to make a plugin work that I have developed myself. What this plugin does, is that it draws a map and then draws the route of the gps that is connected to the database. I want the plugin to work both real-time and for old data. It gets the latitude as the A-series and the longitude as the B-series in the Metrics tab in Grafana.

However, I do not really know what to put in the Select input box (see the picture, sorry for the ugly arrow). When I put in mean() for example, it (of course) only draws 1 point. I would like to plot enough points for the route to be clear, but I don’t want the plugin to be too slow. Ideally, I think it would be nice if 1 in N points if put in the map. Does anyone know how if this is possible and how to do this? Or does anyone know a good alternative for this kind of plugin?

Thanks a lot in advance!