for now, WebSockets are working with HTTP/1.1 (Upgrade), but not with HTTP/2 [Bootstrapping WebSockets with HTTP/2](https://datatracker.ietf.org/doc/html/rfc8441) e.g. already supported by envoy - [Websocket over HTTP/2 or HTTP/3 hops](https://www.envoyproxy.io/docs/envoy/latest/intro/arch_overview/http/upgrades#websocket-over-http-2-or-http-3-hops)
for now, WebSockets are working with HTTP/1.1 (Upgrade), but not with HTTP/2
Bootstrapping WebSockets with HTTP/2
e.g. already supported by envoy - Websocket over HTTP/2 or HTTP/3 hops