How to make Drupal commerce add to cart and reduce items in cart from product page?

Question

Drupal

Drupal commerce adding to the cart and reducing the items in the cart from the product page
Example:
https://www.utkonos.ru/cat/40
I.e. the pros and cons in the product card are not to reduce or add products, but to control the quantity of this product in the basket.

Answer 1

And silence... and like that everywhere that is connected with Drupal, at least version 8. And it’s not that no one knows anything, but simply doesn’t want to talk. I was convinced of this during live communication with "drupalers" offline. I wrote about it on the forum on drupal.org, the record lasted no more than 10 minutes - they don’t like it ...
Well, I’ll join the question, because I already erased the keyboard and “zaddosit” Google, HOW to make these arrows (pluses / minuses) ?