NPM Google Maps Config.js

const GoogleMapsLoader = require('google-maps'); 
GoogleMapsLoader.KEY = '<KEY>';
GoogleMapsLoader.LANGUAGE = 'en';
GoogleMapsLoader.REGION = 'DE';
GoogleMapsLoader.VERSION = '1';
GoogleMapsLoader.LIBRARIES = ['geometry', 'places'];
// init the map
GoogleMapsLoader.load(function(google) {
  const id = document.getElementById('googleMap');

  const options = {
    mapTypeControlOptions: {
      mapTypeIds: ['Styled']
    },
    zoom: 12,
    center: {lat: 51.2598529, lng: 6.8148163},
    disableDefaultUI: true,
    scaleControl: false,
    scrollwheel: false,
    navigationControl: false,
    mapTypeControl: false,
    mapTypeId: 'Styled'
  }

  const styles =
    [{"featureType":"administrative","elementType":"labels.text.fill","stylers":[{"color":"#444444"}]},{"featureType":"administrative.country","elementType":"geometry.stroke","stylers":[{"visibility":"simplified"}]},{"featureType":"landscape","elementType":"all","stylers":[{"color":"#f2f2f2"}]},{"featureType":"poi","elementType":"all","stylers":[{"visibility":"off"}]},{"featureType":"poi.business","elementType":"geometry.stroke","stylers":[{"visibility":"on"}]},{"featureType":"road","elementType":"all","stylers":[{"saturation":-100},{"lightness":45}]},{"featureType":"road","elementType":"geometry.stroke","stylers":[{"visibility":"simplified"}]},{"featureType":"road.highway","elementType":"all","stylers":[{"visibility":"simplified"}]},{"featureType":"road.arterial","elementType":"labels.icon","stylers":[{"visibility":"off"}]},{"featureType":"transit","elementType":"all","stylers":[{"visibility":"off"}]},{"featureType":"transit","elementType":"geometry.stroke","stylers":[{"visibility":"simplified"}]},{"featureType":"water","elementType":"all","stylers":[{"color":"#afb9c2"},{"visibility":"on"}]}];

  const map = new google.maps.Map(id, options);
  const styledMapType = new google.maps.StyledMapType(styles, { name: 'Styled' });

  map.mapTypes.set('Styled', styledMapType);
});