As an alternative...I wonder if there could be a auth process where the user creates a writeable 'space' for a site/app with a one time key in their password ma

As an alternative...I wonder if there could be a auth process where the user creates a writeable 'space' for a site/app with a one time key in their password manager, gives the site/app the key, then the site uploads new login credentials directly into the password manager.