How to correctly record changes in the number of items in the cart in Yandex.Metrica e-commerce?

Question

Yandex.Metrica

The documentation describes 4 methods:
detail, add(with count), remove, purchase.
Standard case:
- the user added the product to the cart - 1 pc.
- opened the basket and changed the quantity to 3 pcs.
The question is how to correctly transfer this change in the number of goods?
add - with count:2, or add - with count:3 ?
Further, he changed his mind and changed the quantity to 1 pc. In that case what to do? Nothing? call remove 2 times? it doesn't have a count...
In general, some kind of nonsense is obtained.
Who set up e-commerce metrics, please give advice on what data to send and what not, so that the reports have a more or less real picture.