Hi, i found solution to enable HTTP3/QUIC for aapanel.
You have to install nginx 1.25.1 version at your panel (you cant install it by the panel it self, you need to modify the bash script installation command to install latest version).
When you finish the nginx 1.25.1 installation, you can read the nginx doc how to enable HTTP3/QUIC here: https://nginx.org/en/docs/quic.html
Wish that nginx 1.25.1 will officially become available from aapanel