Taking this ECharts example https://echarts.apache.org/examples/en/editor.html?c=heatmap-cartesian, I was wondering if it would be somehow possible to apply a border-radius to each square of the heatmap. My goal was that make these squares appear as rounded elements, like that: https://9elements.com/blog/content/images/border-radius-1.png.

I have tried using the series-heatmap.itemStyle.borderRadius property, but that does not seem available.

Any ideas?