Webauthn: We have no way to trigger conditional UI in a custom sign in page.

[kyb3r]

Environment

Latest next-auth@beta

Reproduction URL

https://github.com/kyb3r/next-auth

Describe the issue

Within the implementation of the signIn function from next-auth/webauthn It seems like it was forgotten to pass in true as a second argument in the startAuthentication function from simplewebauthn:

https://simplewebauthn.dev/docs/packages/browser#browser-autofill-aka-conditional-ui

How to reproduce

Try to call the signIn("passkey") function on page load or useEffect() as described in the original pull request implementing webauthn (#8808).

This will cause the modal version of webauthn to pop up.

Expected behavior

The expected behaviour is that autofill information will show up alongside suggested passkeys. Instead we see the modal pop up. This can be fixed by giving us a way to pass true into the second argument of startAuthentication imported from simplewebauthn/browser

Do you think something like signIn("passkey", { autoFill: true }) would be good?