JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&amp;signed_in=true"></script>
<div id="map"></div>

CSS

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

JavaScript

const infoWindow = new google.maps.InfoWindow();

function init() {
    const map = new google.maps.Map(document.getElementById('map'), {
        zoom: 6,
        center: new google.maps.LatLng(39.9646, 30.8259),
        mapTypeId: google.maps.MapTypeId.TERRAIN
    });

    map.addListener('click', () => {
        if (infoWindow) {
            infoWindow.close();
        }
    });

    const istanbulMark = new google.maps.Marker({
        position: new google.maps.LatLng(41.0876, 28.9288),
        map: map,
        label: 'I'
    });

    istanbulMark.addListener('click', () => {
        infoWindow.setContent(`
            <h1>Hi mate</h1>
            <hr>
            <p>Welcome to Ä°stanbul!</p>
          `)
        infoWindow.open(map, istanbulMark);
    });

    const ankaraMark = new google.maps.Marker({
        position: new google.maps.LatLng(39.9162, 32.8437),
        map: map,
        label: 'A'
    });

    ankaraMark.addListener('click', () => {
        infoWindow.setContent(`
            <h1>Hi mate</h1>
            <hr>
            <p>Welcome to Ankara!</p>
          `)
        infoWindow.open(map, ankaraMark);
    });
}

google.maps.event.addDomListener(window, 'load', init);