A new version of the HttpClient RTM (Microsoft.Net.Http 2.1) is now released and available for download as a stable NuGet package.
Since, it is a RTM release, the developers can use the Microsoft.Net.Http 2.1 in production.
What is HttpClient?
It is a networking API that allows the developers to access the resources that are exposed using Http.
Know more about the HttpClient RTM and download it from the Microsoft HTTP Client Libraries 2.1.10 Nuget Gallery page