rel canonical in products with attributes in the url

rel canonical in products with attributes in the url

The jshop atribut link plugin was installed, which adds attributes to the url when they are changed to product pages.
Now the problem is that all these URLs with attributes are duplicates. I would like to add the rel canonical tag for such pages with attributes.
I didn't find any plugins. Something similar on the Internet is nowhere to be found. There is an idea that in the Product canonical plugin you need to somehow slightly change the condition in the function, but there is not enough knowledge.
Product canonical

This plugin specifies the canonical address if the product is one and it is in several categories.
And I have one category and attributes are added to the product name:
katalog/listvennitsa/terrasnaya-doska-velvet-listvennitsa This should be canonical
and in such katalog/listvennitsa/terrasnaya-doska-velvet-listvennitsa? attr[1]=4&attr[2]=7&attr[4]=17
you need to write canonical.
I repeat that there is an idea that the condition in the function somehow in the Product / category canonical plugin needs to be corrected but as there are no competencies
Please, HELP

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Aw: rel canonical in products with attributes in the url

Install Product canonical 4.0.2 (JoomShopping 4.0.0 or higher)

Change code

function onBeforeDisplayProduct(&$product){
$document = JFactory::getDocument();
$maincategory_id = $product->getCategory();
$product_id = JRequest::getInt('product_id');
$category_id = JRequest::getInt('category_id');

$uri = JURI::getInstance();
$liveurlhost = $uri->toString(array("scheme",'host', 'port'));

if ($category_id!=$maincategory_id || $this->params->get('hidemain', '1') == 0){
$url = $liveurlhost.SEFLink('index.php?option=com_jshopping&controller=product&task=view&category_id='.$maincategory_id.'&product_id='.$product_id);
$document->addCustomTag('<link rel="canonical" href="'.$url.'"/>');
}
}

To

function onBeforeDisplayProduct(&$product){
$document = JFactory::getDocument();
$maincategory_id = $product->getCategory();
$product_id = JRequest::getInt('product_id');
$category_id = JRequest::getInt('category_id');

$uri = JURI::getInstance();
$liveurlhost = $uri->toString(array("scheme",'host', 'port'));


$url = $liveurlhost.SEFLink('index.php?option=com_jshopping&controller=product&task=view&category_id='.$maincategory_id.'&product_id='.$product_id);
$document->addCustomTag('<link rel="canonical" href="'.$url.'"/>');

}

Aw: rel canonical in products with attributes in the url

it's not a problem if the canonical url also contains rel canonical?

Aw: rel canonical in products with attributes in the url

No.