How to set the radians of the four corners of the echarts background?

I have been learning how to use ECharts recently.
I want to change the radians of the four corners of the echarts background, like this:

Operating environment:
echarts: 5.4.2
vue3

I tried using three methods.
1. Added option attribute: borderRadius: [20, 20, 20, 20], (this is the answer from chatgpt)

option = {
  backgroundColor :'#999',
  **borderRadius: [20, 20, 20, 20],**
  xAxis: {
    type: 'category',
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
  },
  yAxis: {
    type: 'value'
  },
  series: [
    {
      data: [120, 200, 150, 80, 70, 110, 130],
      type: 'bar'
    }
  ]
};

2. Set the radian of the echarts container itself.

<div ref="EnergyCalendar" style="border-radius: 20px;height: 320px; width: 100%;">
</div>

3. Wrap the div outside the echarts container and set the radian of the div.

<div style="border-radius: 20px;">
  <div ref="EnergyCalendar" style="height: 320px; width: 100%;">
  </div>
</div>

But none of these three methods are effective.

Can someone familiar with ECharts help explain how to implement this feature?
Thank you in advance for your answer!