This feature allows your logged-in customers to save their progress on your configurator.
Users have to be logged-in in order to be able to save their design, as these are saved in the database and linked to their user account.
There are several settings available in Settings > Product Configurator:
List of saved configurations
You can find the list of saved configurations in WooCommerce > Configurations.
For privacy reasons, only the user who saved the design and the admin can see a configuration.