[Solved]-Highchart add a text under single bar in bar chart-Highcharts

You can use data labels configuration for a single point.

  events: {
    load: function() {
      this.addSeries(..., {
          x: 3,
          y: 1,
          dataLabels: {
            useHTML: true,
            formatter: function() {
              var pcnt = (data[this.x].y / dataSum) * 100;
              return '...';
            }
          }
        }]
      }, true);
    }
  }

Live demo: https://jsfiddle.net/BlackLabel/9dmtawg3/

API Reference: https://api.highcharts.com/highcharts/series.column.data.dataLabels