How to add shadow effect on bar chart using ChartJs?

I'm using chartjs 3.9 to build a bar chart. I'm trying to get a shadow effect on the bars like this:

I couldn't find how to do this on the documentation. Can someone help me, please?

This are my datasets:

datasets: [
        {
            label: 'SLP',
            data: [23000, 46000, 40000, 41000, 39000, 25000, 45000, 40500, 41000],
            backgroundColor: gradientBg21,
            borderRadius: 9,
            categoryPercentage: 0.8,
            barPercentage: 0.8
        },
        {
            label: 'AXS',
            data: [19000, 22000, 19000, 42000, 39500, 18000, 22000, 18000, 42000],
            backgroundColor: gradientBg31,
            borderRadius: 9,
            categoryPercentage: 0.8,
            barPercentage: 0.8
        }
    ]

Here's my chart: JsFiddle