Caddy reverse_proxy behind caddy reverse_proxy?

[dadatuputi (Bradford)]

This comment makes me think I have the right idea about tls internal, but it seems it doesn’t work between two caddies?

Tls internal, invalid certificat, lifetime

You’re using tls internal which means Caddy self-manages a CA and issues certs from that. Caddy’s internal CA won’t be trusted by browsers. If you’re using a public domain, your server is publicly accessible, and you want to use a cert from Let’s Encrypt, just remove tls internal and restart Caddy.