JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://canvasjs.com/assets/script/canvasjs.min.js"></script>

<div id="chartContainer" style="height: 300px; width: 100%;"></div>

JavaScript

window.onload = function () {
  var chart = new CanvasJS.Chart("chartContainer", {
    title: {
      text: "Unicode Characters in StripLine Label"
    },
    axisX:{
      stripLines:[
        {      
          value:1935,
          label : "\u25B2",
          color: "red",
          labelFontColor: "red"
        }
      ]
    },
    data: [
      {
        type: "splineArea",            
        color: "rgba(83, 223, 128, .6)",
        dataPoints: [
          { x: 1910, y: 5 }, 
          { x: 1920, y: 9 }, 
          { x: 1930, y: 17}, 
          { x: 1940, y: 32}, 
          { x: 1950, y: 22}, 
          { x: 1960, y: 14}, 
          { x: 1970, y: 25}, 
          { x: 1980, y: 18}, 
          { x: 1990, y: 20}
        ]
      }
    ]        
  });
  chart.render();
}