new Vue({
        el: '#app',
        components: {
          apexchart: VueApexCharts,
        },
        data: {
          
          series: [{
            name: "sales",
            data: [{
              x: '2019/01/01',
              y: 400
            }, {
              x: '2019/04/01',
              y: 430
            }, {
              x: '2019/07/01',
              y: 448
            }, {
              x: '2019/10/01',
              y: 470
            }, {
              x: '2020/01/01',
              y: 540
            }, {
              x: '2020/04/01',
              y: 580
            }, {
              x: '2020/07/01',
              y: 690
            }, {
              x: '2020/10/01',
              y: 690
            }]
          }],
          chartOptions: {
            chart: {
              type: 'bar',
              height: 380
            },
            xaxis: {
              type: 'category',
              labels: {
                formatter: function(val) {
                  return "Q" + dayjs(val).quarter()
                }
              },
              group: {
                style: {
                  fontSize: '10px',
                  fontWeight: 700
                },
                groups: [
                  { title: '2019', cols: 4 },
                  { title: '2020', cols: 4 }
                ]
              }
            },
            title: {
                text: 'Grouped Labels on the X-axis',
            },
            tooltip: {
              x: {
                formatter: function(val) {
                  return "Q" + dayjs(val).quarter() + " " + dayjs(val).format("YYYY")
                }  
              }
            },
          },
          
          
        },
        
      })
    

      <div id="chart">
        <apexchart type="bar" height="380" :options="chartOptions" :series="series"></apexchart>
      </div>