Contrib module service overriding not working

I am using the ‘Path Redirect Import module along with the Redirect module. I am trying to override its service ‘path_redirect_import.importer’ To do this, I have added a service provider and a custom class that extends the service class that I want to override. however, the overridden function is not getting called. Followed this tutorial:

Any suggestions?

1. inside my custom module's src folder, I created MyModuleServiceProvider.php, which contains the following:

   namespace Drupal\my_module;

    use Drupal\Core\DependencyInjection\ContainerBuilder;
    use Drupal\Core\DependencyInjection\ServiceModifierInterface;
    use Drupal\Core\DependencyInjection\ServiceProviderBase;
   
   
    class MyModuleServiceProvider extends ServiceProviderBase implements ServiceModifierInterface {
   
      public function alter(ContainerBuilder $container) {
   
        if ($container->hasDefinition('path_redirect_import.importer')) {
          $definition = $container->getDefinition('path_redirect_import.importer');
          $definition->setClass('Drupal\my_module\MyTestProv');
        }
   
      }
   
    }
   

in the MyTestProv.php

namespace Drupal\my_module;


use Drupal\path_redirect_import\ImporterService;

/**
 * Class ImporterService.
 *
 * @package Drupal\path_redirect_import
 */
class MyTestProv extends ImporterService {
  public static function import($file, array $options) {
    // If I put something here nothing happens
    \Drupal::messenger()->addMessage(t('Lorem ipsum.'));
  }
}