Import config file programmatically on Drupal 9

Import configuration file programmatically on Drupal 9 using config_update contrib module and service

//Update Module settings

\Drupal::service('config_update.config_update')->revert('system.simple', 'mymodule.settings');

// Import a block.

\Drupal::service('config_update.config_update')->import('block', 'mycustomblock');