nginx_proxy_pass_to_HTTPS

    location / {
                    proxy_pass https://example.de;
                    proxy_http_version 1.1;
                    proxy_set_header Accept-Encoding "";
                    proxy_set_header Cache-Control no-cache;
                    proxy_set_header Upgrade $http_upgrade;
                    proxy_set_header Connection 'upgrade';
                    proxy_set_header X-Real-IP $remote_addr;
                    proxy_ssl_server_name on;
    }