Can't get a certificate via caddy for the life of me

[taunnnt0 1]

Hello, trying to get a certificate now for the past three days. My Caddyfile is like so

mysubdomain.dedyn.io {
	reverse_proxy http://localip:port
	tls {
		dns desec {
			token "mytoken"
		}
	}
}

I get the add on for dedyn and make the new caddy file in xcaddy. I run caddy by caddy start. It's happy until it gets to

2026/03/22 16:02:31.017 ←[31mERROR←[0m  tls.obtain      unable to unlock        {"identifier": "mysubdomain.dedyn.io", "lock_key": "issue_cert_mysubdomain.dedyn.io", "error": "remove C:\\Users\\myusername\\AppData\\Roaming\\Caddy\\locks\\issue_cert_mysubdomain.dedyn.io.lock: The system cannot find the file specified."}
2026/03/22 16:02:31.017 ←[31mERROR←[0m  tls     job failed      {"error": "mysubdomain.dedyn.io: obtaining certificate: context canceled"}
2026/03/22 16:02:31.017 ←[34mINFO←[0m   shutdown complete       {"signal": "SIGINT", "exit_code": 0}

Emby is set up to public ports are 80, 443. I do have secure connections are handled by proxy.

What is the issue? Is there a better DDNS to use (that's free)? That's more easy to make a certificate?

Thanks