In the root of this project you will find a service-worder.js.example file. Copy this file to the root public folder
of your project and rename it to service-worker.js. If you have done this correctly you should be able to find the
file on <YOUR_PROJECT_URL>/service-worker.js when your meteor project is running.
The example file contains all the code needed for the push notifications.
If you are feeling adventurous and want to venture out into the world of service worker options, you can. However, keep in mind that when you reload your application, the service worker will already be registered and its content will not be refreshed. Empty cache and hard reload will not help you in this regard.
In chrome it is possible to get a list of all the registered service workers by going to chrome://serviceworker-internals/. Here it is possible to unregister a service worker. Now, when you reload your application, the service worker will register itself again, but now with the updated code. For now I have not figured out how to force a service worker update for all the users of your application.
I do not know where to find comparable features in Firefox. However, their service worker implementation is still rather new. If you find those settings, please let me know and I will update the documentation.
* okay, maybe this seperate file was not entirely necessary, but it is important you do this correctly