You can obtain the CAST Report Generator Core as a ZIP file from the CAST Product Center - this requires a CAST login.
The runtime can be downloaded as an installer from https://dotnet.microsoft.com/download/dotnet-core/2.2 - choose the .NET Core Installer for the 2.2.x runtime that matches your Windows environment:
Package manager instructions are provided for many different Linux distributions at https://dotnet.microsoft.com/download/dotnet-core/2.2 - choose the Package Manager Instructions option here:
Then select the relevant Linux distribution to view the installation instructions:
Supported Operating Systems
CAST Report Generator Core only requires that .NET Core runtime is present on the operating system. Therefore any operating system that supports the installation of .NET Core can be used for the CAST Report Generator Core. CAST has tested Microsoft Windows and CentOS (Linux).
Installing CAST Report Generator Core consists only of unzipping the downloaded ZIP file to a location on the target server, for example: