I guess my question is, what do you want the chart to show prior to the button being clicked? Is there a chart there at all, as in, does the button just show the chart, or is the button supposed to update the data every time the button is clicked?
If it’s the first, then I would just have the button show the chart and the api call won’t be made until the chart is shown. Then for your data source of your chart, set it to the API call. I can’t tell from your screenshots if that’s what you’ve done and the data source is “get data from external api” and then chose which of the response values are to be plotted.