Add graphs from excel workbooks to powerpoint

So I have lets say 3 workbooks and on each first tab of that worbook there is a (pivot)graph.
Now what I would want is VBA code which opens these excel workbooks, then copy the chart and paste it into a powerpoint presentation each chart on a new powerpoint slide.

So it can be rather basic. A loop which goes thru excel sheets and always takes the chart on the first tab.

I see a lot of different code but not what I really can use for powerpoint thru excel vba.
Thanks.

Thanks for tip, but I am not a big fan of external linking.
Also the main goal of the VBA is not making the powerpoint but generating workbooks by division with charts.
I thought adding a button to generated also powerpoint slides to use in a presentation would be nice to have .