I have the feeling that notification sytem dont look into extension langage folders for find template email.

Exemple, in UCP >> notification options, i enable email for my extention's notifications type.

In my vendor\ext\notification\type\exemple class, i have:

	public function get_email_template()

	{

		return 'directory_website_in_queue';

	}

the notification is send, but not the email, with this error:

Unable to find template "directory_website_in_queue.txt" (looked into: ./language/en/email).

and i have a vendor/ext/language/en/email/directory_website_in_queue.txt file

template() method in functions_messenger.php had a third argument for specify a template path, but it is not used in phpbb\notification\method/messenger_base.php :/