如何删除Chart.js x轴的底线？

<canvas id="myChart"></canvas>

var ctx = document.getElementById('myChart').getContext('2d');
var myChart = new Chart(ctx, {
    type: 'bar',
    data: {
        labels: ['Label 1', 'Label 2', 'Label 3'],
        datasets: [{
            label: 'Dataset',
            data: [10, 20, 30]
        }]
    },
    options: {
        scales: {
            x: {
                grid: {
                    display: false // 设置x轴底线不显示
                }
            }
        }
    }
});