No notifications on Bangle.js2 from Gadgetbridge

Yes, Gadgetbridge for Bangle.js and standard Gadgetbridge are basically the same, but the Bangle.js one has internet connectivity, so the app loader works (and apps on the watch can access the internet if you need them to).

But for this to work you do need the Android Integration app installed on the watch. If you're not getting battery level/etc reported than that could be the issue?