Glasshouse is invite-only. Enter the PIN David gave you, plus the Apple ID you'll use with TestFlight.
After you're added: install Apple's free TestFlight app, then watch for the invite email (or tap the link in it). If the build is still in Apple's first-time review, you'll get in the moment it clears (usually ~a day).
⏳ While you wait for the invite, see what your browser already reveals about you → — a separate, live demo of browser-side tracking (different from the app, which reads your phone). Nothing leaves your device.