AmCharts 5 Maps. how to find zoom level?

How to find current zoom Level on wheel event in amcharts 5?

v4 got document below. but there is no document for the same in v5.

https://www.amcharts.com/docs/v4/tutorials/setting-initial-zoom-and-position-of-a-map-chart/#:~:text=Finding%20zoom%20level%20and%20point&text=Zoom%20and%20position%20it%20exactly,by%20accessing%20map's%20zoomLevel%20attribute.

I have tried the below code, it doesn't work properly

 chart.events.on("wheel", function(ev) {
      console.log(chart._downZoomLevel);
    });