JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script> <div id="map_canvas"></div>

CSS

html, body, #map_canvas { margin: 0; padding: 0; height: 100% }

JavaScript

function ChurchControl(churchControlDiv, map) {
churchControlDiv.style.padding = '5px 0px';
var churchControlUI = document.createElement('DIV');
churchControlUI.style.backgroundColor = 'white';
churchControlUI.style.borderStyle = 'solid';
churchControlUI.style.borderWidth = '1px';
churchControlUI.style.borderColor = 'gray';
churchControlUI.style.boxShadow = 'rgba(0, 0, 0, 0.398438) 0px 2px 4px';
churchControlUI.style.cursor = 'pointer';
churchControlUI.style.textAlign = 'center';
churchControlUI.title = 'Click to see Churches';
churchControlDiv.appendChild(churchControlUI);
var churchControlText = document.createElement('DIV');
churchControlText.style.fontFamily = 'Arial,sans-serif';
churchControlText.style.fontSize = '13px';
churchControlText.style.padding = '1px 6px';
churchControlText.style.fontWeight = 'bold';
churchControlText.innerHTML = 'Churches<br>แสดงจำนวนคริสเตียน';
churchControlUI.appendChild(churchControlText);

google.maps.event.addDomListener(churchControlUI, 'click', function() {
    //CHANGED
    alert("clicked");
    toggle(churches);
    if (churchControlText.style.fontWeight == 'bold') {
        churchControlText.style.fontWeight = 'normal';
    } else {
        churchControlText.style.fontWeight = 'bold';
    }
});

google.maps.event.addDomListener(churchControlUI, 'mouseover', function() {
    churchControlUI.style.backgroundColor = '#e8e8e8';
});

google.maps.event.addDomListener(churchControlUI, 'mouseout', function() {
    churchControlUI.style.backgroundColor = 'white';
});
}

function initialize(){
    map = new google.maps.Map(document.getElementById("map_canvas"), {
    // CHANGED      
    center: new google.maps.LatLng(0,0),
    zoom: 7,
    streetViewControl: false,
    mapTypeId: google.maps.MapTypeId.ROADMAP
    });

    var churchControlDiv = document.createElement('DIV');
    
    //CHANGED
    var churchControl = new ChurchControl(churchControlDiv, map);
    churchControlDiv.index = 3;
   ...