On macOS, I was able to get HTTP/3 working in Chrome Canary Version 84.0.4138.0 (Official Build) canary (64-bit) with the following command: /Applications/Google\ Chrome\ Canary.app/Contents/MacOS/Google\ Chrome\ Canary --enable-quic --quic-version=h3-27
It took a reload of the site though, on first load it was only serving HTTP2.
I’m not sure whether Chrome stable supports the required QUIC version, and I’m not sure about Chromium.