1. Add the Configuration Update Manager project to your Drupal installation using the following Composer command:

$ cd /path/to/drupal8
$ composer require drupal/config_update

2. Go to the Extend page and install the Configuration Update Reports module, the user interface for Configuration Update Manager:

3. To visit the configuration reports, go to Configuration in the toolbar under the Development section and click on Configuration synchronization.
4. Go to the Updates Report tab. This provides an overview of configuration reports to generate: by configuration type, module, theme, and profile.
5. Review the System module's configuration. Select the System module from the module's drop-down button.

6. For the system.site row, click on the Show differences button link. This will review a difference report between the default configuration and the current site configuration:

7. Click on the Back to 'Updates report' page to go back to the main report so that the configuration can be reverted.
8. Expand the drop-down button so that you can click on Revert to source:

9. Click on Revert on the confirmation form to finish the operation.
10. The configuration is now reverted to its original installation.