How to find a replacement and replace a broken kickstand?
Managed to find replacement kickstand that would fit my bike. In my case it was Ursus rear  kickstand with 18mm fixing plate (there are also ones with 40mm fixing plate). Very simple to install with just two bolts.

Here is the catalog of Ursus kickstands:
https://ursus.it/products/urban-city/kickstands/