When you scan this it will instant onboard you in a browser. It isn't tied to your current nostr nsec.

It generates an nsec in the background and gives you a simple log in phrase and a backup seed phrase.

Go into the "danger zone" and there you can add your name to get a free custom ln address and a free custom nip05 address.

You will also see a NWC qr code to add to any nostr client.

You don't need to use Amber for safebox as it is isolated.