What caddy does are automatic certs. You set up your web-portal and make a wildcard subdoman that points to your portal. Then you just enter two lines in the config and your new app is up. Lets say you want to put your hone assistant there. You could add hass.portal.domain.tld {reverse_proxy internal.ip:8123 } and it works. Possible with other setups too, but its no hassle