authenticate
Authenticates with an existing passkey (assertion ceremony).
Triggers the system passkey selection/biometric flow. On success, returns the signed assertion that proves the user controls the passkey.
Return
PasskeyAssertionResult with the signed assertion
Parameters
activity
Activity context — required for the CredentialManager system UI
challenge
Custom challenge bytes to include in the assertion. For keyAuthorization, this contains the delegation payload hash.
Throws
on failure