drupal 8 import config programmatically

d8_import_config.php

<?php

// The following snippet updates the filter format configuration.
$config_path = drupal_get_path('module', 'my_custom_module') . '/config/install'; // or any path containing config files theoretically.
$source = new FileStorage($config_path);
$config_storage = \Drupal::service('config.storage');
$config_storage->write('filter.format.basic_html', $source->read('filter.format.basic_html'));