Make a variable permanent, javascript, php

On this Url https://mappingforyou.eu/gallery/osmmap.php?/category/35&v=2

a "category" variable was set to 35. I'd like the page to set that category to 35 permanently. How should I do ?

I'm using https://github.com/Piwigo/piwigo-openstreetmap .

The files are map2.tpl and functions_map. php

Please help.

PS : last time my post was closed without explanation and I was prevented from posting again. This doesn't occur on gis stackechange, but this occurs here and I can't figure out why. I'm here for the purpose of learning and I'm a beginner so please at least give an explanation

    function osm_get_gps($page)
{
    // Limit search by category, by tag, by smartalbum
    $LIMIT_SEARCH="";
    $INNER_JOIN="";
    if (isset($page['section']))
    {
        if ($page['section'] === 'categories' and isset($page['category']) and isset($page['category']['id']) )
        {
            $LIMIT_SEARCH = "FIND_IN_SET(".$page['category']['id'].", c.uppercats) AND ";
            $INNER_JOIN = "INNER JOIN ".CATEGORIES_TABLE." AS c ON ic.category_id = c.id";
        }
        if ($page['section'] === 'tags' and isset($page['tags']) and isset($page['tags'][0]['id']) )
        {
            $items = get_image_ids_for_tags( array_reduce( $page['tags'], 'osm_get_page_tag_id' ) );
            if ( !empty($items) )
            {
                $LIMIT_SEARCH = "ic.image_id IN (".implode(',', $items).") AND ";
            }
        }
        if ($page['section'] === 'tags' and isset($page['category']) and isset($page['category']['id']) )
        {
            $LIMIT_SEARCH = "FIND_IN_SET(".$page['category']['id'].", c.uppercats) AND ";
            $INNER_JOIN = "INNER JOIN ".CATEGORIES_TABLE." AS c ON ic.category_id = c.id";
        }
    }

    $forbidden = get_sql_condition_FandF(
        array
        (
            'forbidden_categories' => 'ic.category_id',
            'visible_categories' => 'ic.category_id',
            'visible_images' => 'i.id'
        ),
        "\n AND"
    );

    /* Get all GPX tracks */
    $query="SELECT i.path FROM ".IMAGES_TABLE." AS i
            INNER JOIN (".IMAGE_CATEGORY_TABLE." AS ic ".$INNER_JOIN.") ON i.id = ic.image_id
            WHERE ".$LIMIT_SEARCH." `path` LIKE '%.gpx' ".$forbidden." ";

    return array_from_query($query, 'path');
}

function osm_get_items($page)
{
    // Limit search by category, by tag, by smartalbum
    $LIMIT_SEARCH="";
    $INNER_JOIN="";
    if (isset($page['section']))
    {
        if ($page['section'] === 'categories' and isset($page['category']) and isset($page['category']['id']) )
        {
            $LIMIT_SEARCH = "FIND_IN_SET(".$page['category']['id'].", c.uppercats) AND ";
            $INNER_JOIN = "INNER JOIN ".CATEGORIES_TABLE." AS c ON ic.category_id = c.id";
        }
        if ($page['section'] === 'tags' and isset($page['tags']) and isset($page['tags'][0]['id']) )
        {
            $items = get_image_ids_for_tags( array_reduce( $page['tags'], 'osm_get_page_tag_id' ) );
            if ( !empty($items) )
            {
                $LIMIT_SEARCH = "ic.image_id IN (".implode(',', $items).") AND ";
            }
        }
        if ($page['section'] === 'tags' and isset($page['category']) and isset($page['category']['id']) )
        {
            $LIMIT_SEARCH = "FIND_IN_SET(".$page['category']['id'].", c.uppercats) AND ";
            $INNER_JOIN = "INNER JOIN ".CATEGORIES_TABLE." AS c ON ic.category_id = c.id";
        }
    }