Add button Add to cart in the block of new products (position displayleftcolumn)

[restaller]

Hello everyone,
 
I am trying to insert an Add to cart button into the block of new products of the displayleftcolumn position, which is displayed on the category pages.
 
A "Product not found" message is displayed.
 
But you can not get the value of the product id in the attribute data-id-product = "..."
The code is located in prestashop\themes\default-bootstrap\modules\blockviewed\blockviewed.tpl:
 

<a class="button ajax_add_to_cart_button btn btn-default" href="{$link->getPageLink('cart, true')}" rel="nofollow"
                        title="{l s='Add to Cart'}" data-id-product="..." data-id-product-attribute="0">    
                        <span>{l s='Add to cart'  mod='blockviewed'}</span>
</a>

 
The data-id-product value is empty because I do not know what to use inside.
 
Would anyone know what to use to get the product id?

[Makip]

Hi All

I Am working on prestashop1.6.11 

The cart is not working, what shall I do.