为什么这个由python-highcharts制作的向下钻取图不能工作？

import json

# 示例数据
data = [
    {"name": "Category 1", "y": 10, "drilldown": "cat1"},
    {"name": "Category 2", "y": 20, "drilldown": "cat2"}
]

# 转换为JSON格式
json_data = json.dumps(data)

Highcharts.chart('container', {
    chart: {
        type: 'column'
    },
    title: {
        text: 'Down Drilldown Chart'
    },
    xAxis: {
        type: 'category'
    },
    yAxis: {
        title: {
            text: 'Value'
        }
    },
    series: [{
        name: 'Category',
        data: JSON.parse('{{ json_data|safe }}')
    }],
    drilldown: {
        series: [{
            name: 'Subcategory',
            id: 'cat1',
            data: [
                ['Subcat 1', 5],
                ['Subcat 2', 3]
            ]
        }, {
            name: 'Subcategory',
            id: 'cat2',
            data: [
                ['Subcat 3', 8],
                ['Subcat 4', 7]
            ]
        }]
    }
});

# 安装必要的Python库
pip install highcharts-python