Thank you Илья and Dinko. What I can see is that haproxy doc suggest using QuicTLS library. The build process is well explained in Dockerfile. That's perfect.
I've also seen some information about haproxy 2.6 configuration for HTTP/3 over QUIC in the following article. I imagine it may be suitable for 2.8 version as well...
https://www.haproxy.com/blog/announcing-haproxy-2-6 -- Best regards, Artur
