Why doesn't AJAX add to cart with variable items work?

Question

WordPress

Simple products are easily added from the product listing (without reloading the page), but when you try to add a variable product, the product page opens.
I noticed that for variable products, in the button (link) "add to cart" there is no get parameter "add-to-cart" (for simple products it is present)
I tried to install the plugin "Woocommerce Add to cart Ajax for variable products", but it does not solved the problem.

Answer 1

To add a variable product to your shopping cart, you must select a product variation. Under standard conditions, a variation can only be selected on the product page.

Answer 2

if this option is suitable avto-market.by/auto/motor-oil/castrol/ I will throw off
the code from the working site