You could try using https://www.printnode.com which is essentially exactly the service that you are looking for. You download and install a desktop client onto the users computer - https://www.printnode.com/download. You can then discover and print to any printers on that user's computer using their JSON API https://www.printnode.com/docs/api/curl/. They have lots of libs here: https://github.com/PrintNode/
