JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>
<div id="chartContainer" style="height: 360px; width: 100%;"></div>

JavaScript

var chart = new CanvasJS.Chart("chartContainer", {
  title:{
    text: "Monthly Weight Analysis"              
  },
  axisX: {
    interval: 1,
    intervalType: "month"
  },
  axisY: {
    title: "Weight (in lbs)"
  },
  data: [{
    type: "column",
    dataPoints: [
      {x: new Date(2020, 00, 00), y: 300},
      {x: new Date(2020, 01, 00), y: 280.7},
      {x: new Date(2020, 02, 00), y: 265},
      {x: new Date(2020, 03, 00), y: 260},
      {x: new Date(2020, 04, 00), y: 250},
    ]
  }]
});

addIndexLabel();
chart.render();


function addIndexLabel() {
  var datapoint;
  for(var i = 0; i < chart.options.data[0].dataPoints.length; i++) {
    datapoint = chart.options.data[0].dataPoints[i];
    datapoint.indexLabel =  CanvasJS.formatNumber((datapoint.y - chart.options.data[0].dataPoints[0].y), "#,##0.##") + " lbs"
  }
}