The script for displaying products in the catalog does not work, provided why?

Question

1C-Bitrix

Good afternoon. There is a task to hide the display of products in the catalog if there is no checkmark in the user field.

Script written:

$arSelect = Array(
                "ID",
                "SECTION_PAGE_URL"
            );
    $arFilter = Array(
                "IBLOCK_ID"            => 34,
                "!UF_SHOW_HEAD_MENU"=> 0,
                "ACTIVE"               => "Y"
            );
    $res      = CIBlockSection::GetList(Array(), $arFilter, false, $arSelect);
    $arTemp   = array();
    while($ob = $res->GetNextElement())
        {
            $arFields                              = $ob->GetFields();
            $arTemp[$arFields["SECTION_PAGE_URL"]] = $arFields;
        }
    unset($res);
    $arTempResult = array();
    foreach ($arResult as &$arMenuItem)
        {
            if ($arTemp[$arMenuItem['LINK']])
            {
                $arTempResult[] = $arMenuItem;
            }
        }
        $arResult = $arTempResult;
        unset($arTemp);
        unset($arTempResult);

but wherever I insert it, it does not function, where to dig?