Components
If you want to programmatically check the Pathauto's Generate automatic URL alias checkbox you can do something like this:
use Drupal\pathauto\PathautoState;
$entity_type = 'node';
$entity_storage = \Drupal::entityTypeManager()->getStorage($entity_type);
$nodes = $entity_storage->loadMultiple();
foreach($nodes as $node) {
$node->path->pathauto = PathautoState::CREATE;
$node->save();
}
For terms just change the entity type to this:
$entity_type = 'taxonomy_term';
To uncheck the field instead of CREATE use SKIP constant:
$node->path->pathauto = PathautoState::SKIP;
In summary, the code snippets provided outline the process of programmatically toggling the automatic URL alias generation feature in Drupal using the Pathauto module.