Saving chart images by API call.
 Download API Copy Link  
We expose the APIs for triggering download via the AgCharts class:
The AgChartInstance can be obtained using the Vue $refs component property to reference our AgCharts tag, which exposes a chart property.
This example demonstrates:
- How to obtain a reference to an 
AgChartInstance. - How to use 
AgChartInstance.download()to start a chart image download. - How to use 
AgChartInstance.getImageDataURL()to create a base64-encoded image URL, and then open it in a new tab.