The steps are 1. Install a 3rd party Passkey manager on your device (Google chrome works), 2. Go to Settings->General->AutoFIll & Passwords, and turn on autofill for Google Chrome, 3. Run the sample app on your device (you need a domain and place a AASA file there), 4. Press "sign up" and make sure to select "save in Google" Notice the operation cancels

sorry the image post got messed up, the image above is the state that works, there was supposed to be another image where it says "Save in Chrome" which doesn't work