ws:// is not encrypted. wss:// is encrypted Think of it as http and https in this regard.

The Umbrel Nostr relay will only work with devcies on your home network/ WiFi. To access the relay while you're outside your home, you can use Tailscale. It's a private VPN. You would need to install this on your node and on your phone. Then launch the Tailscale app before your Nostr client. Then you'd be able to access it.