JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript" src="http://www.highcharts.com/js/testing.js"></script>

<div id="container" style="height: 300px"></div>

JavaScript

var chart = new Highcharts.Chart({

    chart: {
        renderTo: 'container'
    },

    xAxis: {
        categories: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
    },
    
    tooltip: {
        formatter: function() {
            var s = this.y;
            if (this.point.options && this.point.options.custom) {
                s += '<br/>'+ this.point.options.custom;
            }
            return s;
        }
    },

    series: [{
        data: [{
            y: 29.9,
            custom: 'Hello'
        }, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4]
    }]

});