Caddy version: v2.2.0 h1:sMUFqTbVIRlmA8NkFnNt9l7s0e+0gw+7GPIrhty905A=

I am trying to pass pem-encoded client certificate to proxied service via a X-SSL-Cert header, like so:

sub.example.com {
    reverse_proxy 127.0.0.1:8000 {
        header_up X-SSL-Cert {http.request.tls.client.certificate_pem}
    }

    tls {
        client_auth {
            mode require
        }
    }
}