Hello, a suggestion :). Idk if you can, with the package installer setup. However the SW should be in root, it is running in its current form, however it will not work on mobile like that, and fails LH. Woltlab makes a similar error. With their default Favicon info sections. It needs to be in root, for the manifest to read properly. I not sure if this will allow the notifs to work on mobile or not, but as of now they do not. And I will get to testing here later, but it will allow pwa, and the current setup makes you choose PWA or this Push.
I was wrong, apparently your SW location is just fine, I thought it would override root SW, it does not, it adds to it, due to your nav call.
Also, just tested this, on my PWA, works Perfectly, except 2 issues.
1. On both, the browser and the PWA, the notification gives a header logo, (Id prefer it didn't, at all personally) which is fine for most, and I would be fine with, except the image on my site is extremely blown out, and cuts the box its supposed to reside in. It is also like this in mobile, and makes the notif, extremely large (like half the phone screen lol). It does the same on your site, and you see like Myst and thats it. I would suggest, allowing that to be resized, and/or turned off in the settings. I can likely do that for mine for now, but for future less techy people :).
2. The link given, on the notif, is shown as [URL:Mysite-notiftype] Instead of just a link, Also, if you didnt know I dont think that link needs to be description for the notif to take to page. As there is no link on stock Woltlabs notifs. So maybe just a description of the notif type? Ill check into that for you as well, and see what I can do, about fixing it.
Not really a suggestion for the plugin, but just a so you know. or maybe for future plug in :).
This works fully with PWAs, which could be a selling point, to do that is easy. You will need a Root SW, even if its blank, as your Register is on demand, but you can register a Blank SW, and yours will overwrite allowing full PWA, prior to Notifs. So basically just need a blank file named SW.JS in root, and it registered, and if you have not tried PWA yet, you have to make a new manifest. You may be able to do it, with woltlabs in the favicon folders, but I had nothing but issues, so overwrite theirs, in Templates manifest link, to mine.
Oh and thank you so much for this plugin. You are a rockstar!