Use it away from home

At home, the phone reaches Hotline on your computer over your Wi-Fi. To reach it anywhere else, give the phone another way in. Either way, open Hotline on the phone once while you’re home afterwards, so it learns the new way in from the desk.

Your own VPN

Put the computer and the phone on the same private network, then restart Hotline on the computer. The desk listens on that network too, and the phone reaches it wherever you are. Any VPN that gives each device its own address works. For example:

• A mesh VPN such as Tailscale. Install it on the computer and on the phone, signed in to the same account on both. Nothing needs to be exposed to the internet, and no port forwarding is needed.
• WireGuard or your router’s VPN. Connect the phone to the network the computer is on.

The phone shows Reachable over your VPN under the desk once it has seen the desk’s VPN address.

A Hotline server

Pair the desk with a Hotline server and choose it under Settings → Remote → Relay on the computer. The computer dials out to the server, so nothing on your home network has to accept connections, and the server can’t read what passes through it: the phone only trusts the desk’s key. Phones paired after that get the relay in their QR code; phones paired before pick it up the next time they connect at home. A server that only does this, with no agents, can be a Raspberry Pi: Run a relay.