Drupal\Component\Plugin\Exception\PluginNotFoundException: The "node_agent" plugin does not exist

When accessing the page /admin/structure/ai_assistant/add, the error occured:
Drupal\Component\Plugin\Exception\PluginNotFoundException: The "node_agent" plugin does not exist. Valid plugin IDs for Drupal\ai_agents\PluginManager\AiAgentManager are: node_content_type_agent, webform_agent, views_agent, taxonomy_agent, field_type_agent in Drupal\Core\Plugin\DefaultPluginManager->doGetDefinition() (line 53 of /var/www/html/drupal/web/core/lib/Drupal/Component/Plugin/Discovery/DiscoveryTrait.php).