Basically I was able to pass email and phone number verification, but then "Continue" button on the "Apple ID & Privacy " page doesn't work and you can't get around it. No error or description whatsoever, just internal server error in the browser's console.
Turns out it's a known problem and the same button works perfectly fine when pressing it on an Apple device. I haven't tried it in a macOS VM though, but presumably Apple flags such accounts anyway.
Related thread: https://www.reddit.com/r/applehelp/comments/17zawel/continue...
If you want, I can create an account for you on my Mac, email me (email in profile).
[0] https://github.com/seemoo-lab/openhaystack?tab=readme-ov-fil...
[1] https://github.com/seemoo-lab/openhaystack/tree/main/Firmwar...