Hi,
Sorry for the late reply.
Unfortunately I haven’t got any examples on how to achieve this, but you might be able to figure it out by looking at this example code.
To do this you must attach an event handler in custom code like described here: https://spjsblog.com/spjs-charts-for-sharepoint/spjs-charts-for-sharepoint-user-manual/#Attaching_an_event_handler
This code must be added to a *.js file and uploaded to your site and then the file must be referred to in the “Load external JS or CSS” in your chart configuration.
Alternatively you can embed the code in a script editor web part in the site where you are loading the chart. In that case you must wrap it in a script tag.
Best regards,
Alexander