Update to macOS 15.4.
As for Apple Account passwords when migrating contents from an existing Mac, you’ll get asked for each of the Apple Account passwords in use, as the various associated hunks are updated. That can be the Apple Account used for the install, and for any accounts used for installed apps, for instance.
Depending on the configuration here, there will also be the Mac account login password, and can potentially be an Apple Account login verification code or an iCloud Keychain code, all of which are separate from the Apple Account