Select Tools > NuGet Package Manager > Manage NuGet Packages for Solution.

Click the 'Browse' link/tab, then type 'Kartris' in the search box. You should find the Kartris package.

Click to select this, then check the box to install to the project you've just set up. Click the Install button.

Visual Studio will show you a list of dependencies. Click OK to proceed with the installation. You will also need to approve some licenses for dependencies. The required Kartris files will then be downloaded to your web.