This is a longshot but does anybody happen to know what the Procfile should look like for a Caddy site on Heroku?

There's a bunch of buildpacks but I can't find an example of a Procfile anywhere

Are you having a specific problem? I don't have any experience with Caddy. But for Heroku you must bind your web process to the PORT environment variable. Furthermore, to do that with Caddy you'd use the -port cmdline flag.

So I'm guessing your Procfile would turn out something like this:

web: caddy -port $PORT

If you have other concerns, then you'll need to be more specific. Hopefully that helps.

that's definitely doing something, now it's saying

error presenting token: Could not start HTTPS server for challenge -> listen tcp :443: bind: permission denied

Ug.

HEY FUTURE PEOPLE:
Put "tls off" in your CaddyFile if you're using Heroku with SSL disabled, you're welcome