SSL caddy with droplet

Created a fresh droplet and decided to test it with caddy to serve with https. Following this awesome article showing how to use caddy inside droplet. Everything went well up until step 4 (Enabling Automatic TLS with Let’s Encrypt).

Basically, when i did all the steps in the step 4. I go to my domain and received ERR_SSL_PROTOCOL_ERROR error.

Caddyfile

<domainname>.com.my {
    root * /var/www
    encode gzip
    file_server

    tls {
      dns digitalocean dop_v1_...
    }
}

/etc/systemd/system/caddy.service

[Service]
Type=notify
User=caddy
Group=caddy
Environment=DO_AUTH_TOKEN=dop_v1_...
ExecStart=/usr/bin/caddy run --environ --config /etc/caddy/Caddyfile
ExecReload=/usr/bin/caddy reload --config /etc/caddy/Caddyfile
TimeoutStopSec=5s
LimitNOFILE=1048576
LimitNPROC=512
PrivateTmp=true
ProtectSystem=full
AmbientCapabilities=CAP_NET_BIND_SERVICE

status

● caddy.service - Caddy
     Loaded: loaded (/etc/systemd/system/caddy.service; enabled; vendor preset: enabled)
     Active: active (running) since Fri 2024-06-21 11:20:43 UTC; 23min ago
       Docs: https://caddyserver.com/docs/
   Main PID: 152795 (caddy)
      Tasks: 8 (limit: 2220)
     Memory: 10.8M
        CPU: 439ms
     CGroup: /system.slice/caddy.service
             └─152795 /usr/bin/caddy run --environ --config /etc/caddy/Caddyfile

any idea what might causing this issue?