How I did this

Chart.elements.Line.prototype.draw = function () {
    
    // Chart.elements.Line.prototype.draw.apply(this, arguments);

    var scale = this.scale

    // draw linesasd
    this._chart.ctx.save();
    this._chart.ctx.strokeStyle = '#ff0000';
    var points = this._chart.getDatasetMeta(1).data;
		// debugger;
  
    var point_x = points[0]._model.x;
    var point_y = points[0]._model.y;
    for(var point of points){
      ctx.strokeStyle="#FF0000";
      this._chart.ctx.beginPath();
      this._chart.ctx.lineWidth = 3;
      this._chart.ctx.moveTo(point_x, point_y);
      this._chart.ctx.lineTo(point._model.x, point._model.y);
      console.log(point._model.x);
      
      point_x = point._model.x;
      point_y = point._model.y;
      this._chart.ctx.stroke();
  
    }
    

    this._chart.ctx.restore();
  }



var data = {
  labels: ["January", "February", "March", "April", "May", "June", "July", "August", "September"],
  datasets: [
    {
      label: "My First dataset",
      fillColor: "rgba(220,220,220,0.2)",
      strokeColor: "rgba(220,220,220,1)",
      pointColor: "rgba(220,220,220,1)",
      pointStrokeColor: "#fff",
      pointHighlightFill: "#fff",
      pointHighlightStroke: "rgba(220,220,220,1)",
      data: [28, 48, null, null, null, null, null, null, null]
    },
    {
      label: "My Second dataset",
      fillColor: "rgba(151,187,205,0.2)",
      strokeColor: "rgba(151,187,205,1)",
      pointColor: "rgba(151,187,205,1)",
      pointStrokeColor: "#fff",
      pointHighlightFill: "#fff",
      pointHighlightStroke: "rgba(151,187,205,1)",
      data: [null, null, 40, 19, 86, 27, 90, null, null]
    },
    {
      label: "My Third dataset",
      fillColor: "rgba(151,205,187,0.2)",
      strokeColor: "rgba(151,205,187,1)",
      pointColor: "rgba(151,205,187,1)",
      pointStrokeColor: "#fff",
      pointHighlightFill: "#fff",
      pointHighlightStroke: "rgba(151,205,187,1)",
      data: [null, null, null, null, null, null, null, 24, 32]
    }
  ]
};

var ctx = document.getElementById('chart').getContext('2d');

// Chart.elements.Line.prototype.draw = function() {
//   // alert('asd')
// }

var myLineChart = new Chart(ctx, {
    type: 'line',
    data: data
});