LocaltoNet first tunnel for localhost site, which type and local address do I use

Use an HTTP tunnel first, and point it at the exact local thing that already opens in your browser, usually 127.0.0.1:3000 or localhost:3000 with whatever port your app is on. The main gotcha for me was the port, not the host name, so if your app is actually on 5173 or 8000 and you put 3000, the tunnel "works" but shows the wrong thing.

Yep, and one extra gotcha is binding. If your dev server is listening only on a specific interface, try switching it to 0.0.0.0 in the app config if the tunnel page comes up blank or errors, I've hit that with Vite before.

For verification, I usually check the public URL in a private tab first, then test on phone data so I know I'm not accidentally seeing a cached local result.

Turn off your phone Wi-Fi and open the exact public URL LocaltoNet shows in the tunnel list or details pane, that is the only check I trust for first-time setup. Browser tabs on the same PC can mislead you, but a phone on cellular will tell you immediately whether the tunnel is actually reachable from outside.

Open the public URL from your phone in a normal tab and do one tiny change on the page first, like add a weird word to the title or body, so you instantly know you're seeing your machine through the tunnel and not some old page. I've had that save me a bunch when the page "loaded fine" but I wasn't actually looking at the current local app.