Be aware that very few HTTP clients have HTTP/2 support, e.g. in order for the web and app dotnet tools to call HTTP/2 web servers it needed a special configured HttpClient with a custom WinHttpHandler.
It’s useful if you’re only serving browsers or gRPC clients which natively support HTTP/2 otherwise you’re likely to run into issues with most HTTP Clients.
We’re not using ASP.NET Core yet - it’s a self hosting executable.
In any case, the browser developer tools are reporting HTTP/2 as protocol for requests on our office machines so it seems to be working. I just couldn’t find a clear answer on the prerequisites in terms of Windows/.NET versions and things like that (e.g. implemented as a HttpListener feature that is available starting from …). And the application has to be backwards compatible with older Windows versions up to a point.
Your link at least gives a starting point, so thanks for that!