ChronoPay is one of the leading operators of online payments in Russia, consisting of a group of companies with branches in several countries.
Please find more informartion about how to install plugins here.
The plugin is provided absolutely for free and includes source code. Find the project Github repository here for version 4.40.
You can also find the project Github repository here for previous versions.
Note: This plugin was originally developed by nopCommerce team. And now it's upgraded and maintained by nopStation.