finalgeo
In brave/vanadium/chromium:
3 dots top right > settings > site settings > background sync (for me, background sync is at the bottom).
Enable
failed to save WebPush token
Although, this seems like a notification permission error
Site is listed in browser and allowed notification
browsers are allowed notifications in android settings
Weird. Reboot your phone or vanadium required me to force close it then reopen for my changes to settings to take affect.
Try my suggestion in brave and vanadium?
Found this for a test. Worked for me in vanadium. I have background sync off but you'll likely want it on.
https://simple-push-demo.vercel.app/
That website mentions "FCM." Do you have google play services installed with the network permission?