Change quantity of item when added to cart

Hi,

I am stuck in something I would like to implement on my Woocommerce.
I have variable products with a quantity attribute. Price depends on quantity.
Thing is, my quantity is an attribute so in my cart it is not the right quantity… I wanted to change this quantity with a function in order to replace it with my attribute, and then multiplicate quantity * price to have the right total on the right of the cart.

Do you know if this could be possible ? I hanven’t been able to find any solution for this.

I tried something like this :

add_action('woocommerce_loop_add_to_cart_link', 'change_quantity_cart');
function change_quantity_cart( $cart_object ){
    foreach( $cart_object->get_cart() as $cart_item_key => $cart_item) {
        $item_id = $cart_item['product_id']; // Item Id or product ID
        $marquage = $cart_item['variation']['attribute_pa_marquage'];
        $cart_object->set_quantity($cart_item_key, $marquage, true);
    }
}

I can provide you any other information you could need.

Thank you !