JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<div id="container" style="height: 400px"></div>
<select id="ChType">
    <option value="line">line</option>
    <option value="column">column</option>
</select>
<select id="ChType2">
    <option value="line">line</option>
    <option value="column">column</option>
</select>

JavaScript

$('#ChType').change(function(){
         var series;
     
         for ( i = 0 ; i < chart.series.length ; i++ ) {
                if ( chart.series[i].name == 'MyData1' ) {
                    series = chart.series[i];
                   
                }                
            } 
                     //var series = chart.series[0]
                     var newType = series.type == $('#ChType').val() ? $('#ChType').val() : $('#ChType').val();
                     newType = newType.toLowerCase();//testing
                         changeType(series, newType);
                        
                         
                   })
$('#ChType2').change(function(){
                     var series;
                     
                     
         for ( i = 0 ; i < chart.series.length ; i++ ) {
                if ( chart.series[i].name == 'MyData2' ) {
                    series = chart.series[i];
                   
                }                
            } 
                     var newType = series.type == $('#ChType2').val() ? $('#ChType2').val() : $('#ChType2').val();
                     newType = newType.toLowerCase();//testing
                         changeType(series, newType);
                   })

function changeType(series, newType) {
                        var dataArray = [],
                            points = series.data;
                        series.chart.addSeries({
                            type: newType,
                            name: series.name,
                            color: series.color,
                            data: series.options.data
                        }, false);
                        series.remove();
                    }
var chart;

$(document).ready(function () {
    chart = new Highcharts.Chart({
        chart: {
            renderTo: 'container',
            zoomType: 'x'
        },
        yAxis: {
            type: 'double',
            min: 0
        },
        xAxis: {
            type:...