Referring to my older post on Caddy Server < 2.0 (https://www.odoo.com/forum/help-1/question/caddy-server-reverse-proxy-how-to-configure-virtual-hosts-for-odoo-146789) here is an update for Caddy Server Version 2 (https://caddyserver.com/):

Prerequisites:

Set-up and deploy Caddy Server according to your preferences, preferably on a dedicated server.
Set "proxy_mode = True" in your odoo.conf file and use the appropriate dbfilter setting if necessary.

Configuration:

Create your Caddyfile (vhost configuration) like this:

example.com { #only if you like to redirect to www.example.com
    redir https://www.example.com{uri} 
}
www.example.com {
    reverse_proxy http://xxx.xxx.xxx.xxx:8069 { 
        header_up X-Forwarded-Proto https
        header_up X-Forwarded-Host {host}
        header_up X-Url-Scheme {scheme}
        header_up X-Real-IP {remote}
    }

    reverse_proxy /longpolling/* http://xxx.xxx.xxx.xxx:8072 { # in case you use it 
    }


    encode gzip zstd
    file_server
    log
}