ChartJs (v 2.7.3) - border radius didn't applied

Question

I want border radius in my chart. but all method doesn't work. how can I apply it?

I tried plugins, option:elements. but all method didnt work

I can't change the version of chart js since my project is made by version 2.7.3.

var hwajuStockinChart = new Chart(hwajuStockin, {
    type: 'horizontalBar',
    data: {
        labels: dataHwaju.stockin.name,
        datasets: [
            {
                label:"완료 입고량",
                backgroundColor: [
                    "rgba(64, 0, 255, 0.5)",
                    "rgba(0, 255, 255, 0.5)",
                    "rgba(4, 180, 4, 0.5)",
                    "rgba(132, 132, 132, 0.5)",
                    "rgba(223, 1, 1, 0.5)",
                    "rgba(255, 128, 0, 0.5)"
                ],
                data: dataHwaju.stockin.qty_per
    }, {
                label:"남은 입고량",
                data: dataHwaju.stockin.req_per

    }
  ]
    },
    options: {
        responsive:false,
        legend: {
            display: true,
            labels: {
                fontSize: 0,
                padding: 0,
                boxWidth: 0,
            },
        },
        title: {
            display: false
        },
        scales:{
            xAxes:[{ 
                    stacked:true
                  }],
            yAxes:[{ 
                    stacked:true,
                    gridLines: { 
                        display: false, 
                        drawBorder: false,
                    },
                  }]
        }
    }
});

I add following codes in options:{}

        elements: {
            rectangle: {
                borderRadius: 10
            }
        }

but it didn't work.