You can always log into your store by clicking on the "Manage service" button on the website nic.ru in the "Manage your account" section — "Services" — "Hosting, mail, website builder". In case of loss of data, to log into the store, you need to:
Click on the link sent in the email, enter a new password and click "Change password."
All manuals can be found on Ecwid support page.