Sign in with the launcher.

Ember accounts are your Minecraft account, so there's no password here. The launcher — where you already signed in with Microsoft — vouches for you.

1. Open the Ember launcher.
2. Go to Settings → Website account and click Open my account. Your browser opens already signed in.
3. On another device? Click Show a code instead and type it here. Codes work once and expire after 5 minutes.