If you have problems with web push or with other service worker based technologies on Firefox, then you probably want to use the Firefox developer tools for debugging.
In order to open the service worker tools, open Firefox and from the menu bar go to Tools -> Web Developer -> Service workers (or use this URL: about:debugging#workers). Then find your service worker and click the Debug button.
The tools are useful for two main reasons:
- Make sure that the source code you are running is updated (the update of a service worker can be tricky)
- See the console messages and errors for that service worker (each service worker has its own console, which is separate from the normal console of the website)
You can find more details in this post. Also note that Chrome provides a similar tool.