How to make correct requests on someone else's API?

Question

JavaScript

Hello, dear experts, there was a requirement to get the availability of goods and parse it from a well-known store (Leroy Merlin). It uses Bitrix and POST request:

https://leroymerlin.ru/bitrix/php_interface/ajax/nalInStock.php

Parameters: csrf_token=1e970cfd899a4eb76f9b8fccfb0e&art=12717375&tmpl=redesign
Token, article and template like
I can't get at least something for this request, the button itself is on the product page (for example: https://leroymerlin.ru/product/sostav-remontnyy -16... "See availability in other stores"
In general, is it possible to somehow get the quantity of goods?