Looking through internet I already know, that in order to do this I have to use some module, as it's not in magento 2. So I found some messages that pointed to extenstions like Amasty Multi Warehouse Inventory ( https://amasty.com/multi-warehouse-inventory-for-magento-2.html ) but either I'm blind, or that's not exactly what I'm looking for.
I have single Magento installation, I've created two different websites, each website has one store and one store view. The first website is for US (lets say address is shop.us) clients and the second one is for German clients (address is shop.de). I have physical warehouses in both these countries and I want to associate each of these warehouses to one of the websites - warehouse in US to website US, warehouse in Germany to website DE. US warehouse has 40 product X, and German has only 25 of product X. Because of this, I don't want people who enters shop.us to be able to buy more than 40 of product X, but as far as I checked, I'm not able to set it in the Amasty Multi Warehouse Inventory and I wasn't able to find demo of other modules.
Also I don't want to create two magento instances or create two different products for warehouse US and warehouse DE, I need one product, that will be available for both websites, but its max quantity will be set per warehouse.
Is it possible to achieve, and if so, how?
Thanks in advance! :)