nsec.app appears to be the only available NIP-46 provider at the moment.
I always have trouble logging into Amber's bunker URL.
Discussion
With Amber try switching the Notification type setting to Direct, might help.
My Android phone lacks the Direct option in the notification settings. I have tried several notification options, but none have been effective.
Maybe try to update Amber to latest version, please
It is the latest.
The login method of simply inputting the bunker URL is unsuccessful, but there is no problem with logging in with Amber. I am still learning about nip46.
Strange, I just tried to log into npub.pro with Amber using bunker url, worked fine - after pasting the url I had to go back to Amber to confirm the permissions, then it worked.