This is a custom application that has been simplified for demonstration. Markers can be added to the map and labeled with the New Marker button on the left. The markers on the map can be dragged around as well. Changes to the map location and zoom level are stored when the map is saved. Use the New Map button to make a new map in a separate tab. This allows multiple maps for users to view on the same page. The title for each map can be changed in the title input box.
To view the maps as users would see it, save it and click the view link in the header.
I programmed this application using Vue. Each map and each marker is a component and the map icons are svg images. The map data is saved as a json string and stored as a cookie that is retrieved on the view page.