1. index.html has a div to show Map
2. map_script.js - javascript to draw multiple markers on Google Map
3. Link to Google Map API

Automatically center the map fitting all markers on the screen

NOTE

Please put your Google console API key in index.html

<script src="https://maps.googleapis.com/maps/api/js?key=GOOGLE_API_KEY&callback=initiateMap" 
async defer></script>

Get your lat, long list and pass it to var locations in map_script.js

var locations = [
                   [31.5546, 74.3572],
                   [34.0150, 71.5805],
                   [30.1830, 66.9987],
		                …
		                …		
                    ];

For more details, read this post

Cheers!