Modified from (https://simonh1000.github.io/2019/08/elm-google-map-webcomponent/)
mkdir test_project
cd test_project
npm init
(This will ask you several questions. Answer them and confirm before proceeding.)
npm install --save @em-polymer/google-map
npm install --save elm@0.18.0-exp5
npm run dev
//npm i @em-polymer/google-map import * as map from "./assets/@em-polymer/google-map/google-map"; //import * as marker from "@em-polymer/google-map/google-map-marker";
open localhost:3000