Form::register

public function register($formId): RetargetingResponse;

/**
 * Unlink.
 *
 * @param string $id.
 *
 * @return bool
 */
abstract public function unlink(string $id): bool;


/**
 * Get registered groups.
 *
 * @return string[]
 * @throws BitrixMainArgumentException
 * @throws BitrixMainObjectPropertyException
 * @throws BitrixMainSystemException
 */
public function getRegisteredGroups(): array
{
	$rows = InternalsCallbackSubscriptionTable::getList([
		'select' => ['GROUP_ID'],
		'filter' => [
			'=TYPE' => static::TYPE_CODE,
		]
	])->fetchAll();

	return array_column($rows, 'GROUP_ID');
}