$ caddy reverse-proxy --from :2080 --to :9000

$ curl -v 127.0.0.1:2080

:2080

reverse_proxy :9000

This is the Caddyfile for h2jammy.yushei.ne

# The Caddyfile is an easy way to configure your Caddy web server.
#
# Unless the file starts with a global options block, the first
# uncommented line is always the address of your site.
#
# To use your own domain name (with automatic HTTPS), first make
# sure your domain's A/AAAA DNS records are properly pointed to
# this machine's public IP, then replace ":80" below with your
# domain name.

h2jammy.yushei.net {
        # ssl certificate from cerbot
        # tls /etc/letsencrypt/live/h2jammy.yushei.net/fullchain.pem /etc/letsencrypt/live/h2jammy.yushei.net/privkey.pem
        tls /etc/caddy/fullchain.pem /etc/caddy/privkey.pem

        # Set this path to your site's directory.
        root * /usr/share/caddy

        # Enable the static file server.
        file_server

        # Another common task is to set up a reverse proxy:
        # reverse_proxy localhost:8080

        # Or serve a PHP site through php-fpm:
        # php_fastcgi localhost:9000
}

http://h2jammy.yushei.net:43889 {
        # ssl certificate from cerbot
        # tls /etc/letsencrypt/live/h2jammy.yushei.net/fullchain.pem /etc/letsencrypt/live/h2jammy.yushei.net/privkey.pem
        # tls /etc/caddy/fullchain.pem /etc/caddy/privkey.pem
        log {
                 output file /var/log/caddy/access.log
        }

        reverse_proxy / http://orangepi5.yushei.net:43888 {
                header_up Host {host}
                header_up X-Real-IP {remote}
                header_up X-Forwarded-For {remote}
                header_up X-Forwarded-Proto {scheme}
        }
}

# Refer to the Caddy docs for more information:
# https://caddyserver.com/docs/caddyfile

And this is the Caddyfile for gorangpi5.yushei.net


# https://github.com/dbohdan/caddy-markdown-site
# Copyright (c) 2021 D. Bohdan.  License: MIT.

http://orangepi5.yushei.net:43888 {
        log {
                 output file /var/log/caddy/access.log
        }

        root * demo
        # root * /opt/munetakaJupyterHub

        # send http for nginx server
        # protocols h2c

        encode gzip

        file_server browse
        # browse
        templates

        @media {
                path /favicon.ico
                path /media/*
        }
        @templates {
                path /templates/*
                not path /templates/*.css /templates/*.js
        }
        @markdown {
                path_regexp \.md$
        }
        @markdown_exists {
                file {path}.md
        }

        handle @media {
                file_server
        }
        handle @templates {
                error 403
        }
        handle @markdown {
                rewrite * /templates/index.html
        }
        handle @markdown_exists {
                map {path} {caddy_markdown_site.append_to_path} {
                        default extension
                }
                rewrite * /templates/index.html
        }

        handle_errors {
                file_server
                templates

                @markdown_index_exists_404 {
                        file {path}/index.md
                        expression `{http.error.status_code} == 404`
                }

                handle @markdown_index_exists_404 {
                        map {path} {caddy_markdown_site.append_to_path} {
                                default index
                        }
                        file_server {
                                status 200
                        }
                        rewrite * /templates/index.html
                }
                handle {
                        rewrite * /templates/error.html
                }
                # reverse_proxy http://h2jammy.yushei.net:43999
        }

Both running caddy server. Wht http://h2jammy.yushei.net:43889 retriev nothing?